| Doubles | |
|---|---|
| 1991 European Indoor Championships | |
| Champions |  Petr Korda Karel Nováček |
| Runners-up |  Jan Siemerink Daniel Vacek |
| Final score | 3–6, 7–5, 7–5 |
Pieter Aldrich and Danie Visser were the defending champions, but Aldrich did not compete this year. Visser teamed up with Neil Broad and lost in semifinals to Jan Siemerink and Daniel Vacek.
Petr Korda and Karel Nováček won the title by defeating Jan Siemerink and Daniel Vacek 3–6, 7–5, 7–5 in the final. [1]
Udo Riglewski / Michael Stich (semifinals)
Neil Broad / 
Danie Visser (semifinals)
Steve DeVries / 
David Macpherson (first round)
Ronnie Båthman / Rikard Bergh (first round)| First round | Quarterfinals | Semifinals | Final | ||||||||||||||||||||||||
| 1 | U Riglewski M Stich | 4 | 7 | 6 | |||||||||||||||||||||||
| J Brown S Melville | 6 | 5 | 3 | 1 | U Riglewski M Stich | 3 | 6 | 6 | |||||||||||||||||||
| V Flégl S Kruger | 6 | 7 | 7 | V Flégl S Kruger | 6 | 1 | 4 | ||||||||||||||||||||
| Q | J Kriek J Svensson | 7 | 6 | 6 | 1 | U Riglewski M Stich | 6 | 7 | 4 | ||||||||||||||||||
| 4 | R Båthman R Bergh | 2 | 3 | P Korda K Nováček | 7 | 6 | 6 | ||||||||||||||||||||
| K Curren K Jones | 6 | 6 | K Curren K Jones | 4 | 6 | 4 | |||||||||||||||||||||
 J Lozano  G Luza | 7 | 3 | 4 | P Korda K Nováček | 6 | 4 | 6 | ||||||||||||||||||||
| P Korda K Nováček | 5 | 6 | 6 | P Korda K Nováček | 3 | 7 | 7 | ||||||||||||||||||||
| T Nijssen C Suk | 5 | 6 | 2 | J Siemerink D Vacek | 6 | 5 | 5 | ||||||||||||||||||||
| E Jelen CU Steeb | 7 | 0 | 6 | E Jelen CU Steeb | 6 | 1 | 6 | ||||||||||||||||||||
| J Siemerink D Vacek | 6 | 7 | J Siemerink D Vacek | 4 | 6 | 7 | |||||||||||||||||||||
| 3 | S DeVries D Macpherson | 3 | 5 | J Siemerink D Vacek | 6 | 7 | |||||||||||||||||||||
| C Beckman S Salumaa | 6 | 1 | 4 | 2 | N Broad D Visser | 3 | 6 | ||||||||||||||||||||
| HJ Davids L Pimek | 3 | 6 | 6 | HJ Davids L Pimek | 4 | 6 | |||||||||||||||||||||
 N Aerts R Acioly | 1 | 6 | 4 | 2 | N Broad D Visser | 6 | 7 | ||||||||||||||||||||
| 2 | N Broad D Visser | 6 | 4 | 6 | |||||||||||||||||||||||
The 1990 Cincinnati Open, was a tennis tournament played on outdoor hard courts. It was the 91st edition of the tournament and was part of the 1990 ATP Tour. It took place in Cincinnati, Ohio, United States from August 13 through August 20, 1990. Ken Flach and Robert Seguso were the defending champions, but lost in the second round to Sven Salumaa and Byron Talbot. Darren Cahill and Mark Kratzmann won in the final, 7–6, 6–2, against Neil Broad and Gary Muller.
John Fitzgerald and Anders Järryd were the defending champions but lost in the first round to Jonathan Canter and Bruce Derlin.
Wayne Ferreira and Yevgeny Kafelnikov were the defending champions but lost in the first round to David Rikl and Daniel Vacek.
Cyril Suk and Daniel Vacek were the defending champions but they competed with different partners that year, Suk with Hendrik Jan Davids and Vacek with Richey Reneberg.
Paul Annacone and Christo van Rensburg were the defending champions. Annacone competed alongside Kelly Evernden but lost in the semifinals, while van Rensburg played with Kevin Curren and lost in the quarterfinals.
Darren Cahill and Mark Kratzmann won the title, defeating Udo Riglewski and Michael Stich 7–5, 6–2, in the final.
Pieter Aldrich and Danie Visser were the defending champions, but lost in the first round to Paul Haarhuis and Mark Koevermans.
Scott Davis and David Pate won the title, defeating Patrick McEnroe and David Wheaton 6–1, 4–6, 6–4, 5–7, 9–7, in the final. This was Pate's first Grand Slam title and final, despite gaining the World No. 1 ranking two weeks earlier.
John Fitzgerald and Anders Järryd lost in the third round to McEnroe and Wheaton. It was their only Grand Slam loss of the year, as they would go on to win the following three majors in 1991.
Arnaud Boetsch and Olivier Delaître were the defending champions, but lost in the semifinals this year.
Richard Krajicek and Jan Siemerink were the defending champions, but Krajicek did not participate this year. Siemerink partnered Daniel Vacek, losing in the semifinals.
Daniel Orsanic and Jan Siemerink were the defending champions, but Orsanic did not compete this year. Siemerink teamed up with Ellis Ferreira and lost in semifinals to Wayne Arthurs and Neil Broad.
This article displays the qualifying draw for men's singles at the 1991 Australian Open.
Ellis Ferreira and Jan Siemerink were the defending champions, but competed this year with different partners. Ferreira teamed up with Patrick Galbraith and lost in quarterfinals to tournament winners Donald Johnson and Francisco Montana, while Siemerink teamed up with Menno Oosting and lost in first round to Pablo Albano and Àlex Corretja.
Kelly Jones and Robert Van't Hof were the defending champions, but Jones did not compete this year. Van't Hof teamed up with Laurie Warder and lost in the quarterfinals to Gary Muller and Danie Visser.
Patrick Galbraith and Danie Visser were the defending champions, but competed this year with different partners. Galbraith teamed up with Grant Connell and lost in the semifinals to Jim Courier and Mark Knowles, while Visser teamed up with Laurie Warder and lost in the second round, also to Courier and Knowles.
Wally Masur and Jason Stoltenberg were the defending champions, but competed this year with different partners. Masur teamed up with Mark Kratzmann and lost in the semifinals to Jim Grabb and Richey Reneberg, while Stoltenberg teamed up with Todd Nelson and lost in quarterfinals to Pieter Aldrich and Danie Visser.
Jim Grabb and Patrick McEnroe were the defending champions, but lost in the first round to Scott Davis and Tim Wilkison.
Yevgeny Kafelnikov was the defending champion, but did not compete this year.
Martin Damm and Brett Steven were the defending champions, but none competed this year.
Stefan Edberg and Petr Korda were the defending champions, but lost in the first round to Gary Muller and Danie Visser.
Paul Haarhuis and Mark Koevermans were the defending champions, but competed this year with different partners. Haarhuis teamed up with Jacco Eltingh and lost in the semifinals to Henrik Holm and Anders Järryd, while Koevermans teamed up with Jan Apell and lost in the first round to Javier Sánchez and Daniel Vacek.
Pieter Aldrich and Danie Visser were the defending champions, but Aldrich did not compete this year. Visser teamed up with Gary Muller and lost in the quarterfinals to Nick Brown and Richard Vogel.