The 1988 Nabisco Grand Prix was the only men's tennis circuit held that year. It incorporated the four grand slam tournaments, three World Championship Tennis tournaments and the Grand Prix tournaments.
The 1994 Swedish Open was a men's tennis tournament played on outdoor clay courts in Båstad, Sweden that was part of the World Series of the 1994 ATP Tour. It was the 47th edition of the tournament and was held from 4 July until 11 July 1994. Unseeded Bernd Karbacher won the singles title.
The 1988 Athens Open was a men's tennis tournament played on outdoor clay courts in Athens in Greece that was part of the 1988 Nabisco Grand Prix. It was the third edition of the tournament and was held from 13 June 13 until 20 June 1988. Eighth-seeded Horst Skoff won the singles title.
The 1990 Geneva Open was a men's tennis tournament played on outdoor clay courts that was part of the World Series of the 1990 ATP Tour. It was the 11th edition of the tournament and was played at Geneva in Switzerland from 10 September through 17 September 1990. Second-seeded Horst Skoff won the singles title.
The 1988 CA-TennisTrophy was a men's tennis tournament played on indoor carpet courts at the Wiener Stadthalle in Vienna, Austria that was part of the 1988 Nabisco Grand Prix. It was the 14th edition of the tournament and ran from 17 October through 24 October 1988. Unseeded Horst Skoff won the singles title.
The 1990 CA-TennisTrophy was a men's tennis tournament played on indoor carpet courts at the Wiener Stadthalle in Vienna, Austria and was part of the World Series of the 1990 ATP Tour. It was the 16th edition of the tournament and was held from 15 October through 22 October 1990. Unseeded Anders Järryd won the singles title.
The 1988 Swedish Open, also known as the Volvo (Ladies) Open was a combined men's and women's tennis tournament played on outdoor clay courts held in Båstad, Sweden and was part of the Grand Prix circuit of the 1988 Tour, as well as the Category 1 tier of the 1988 WTA Tour. It was the 41st edition of the tournament and was held from 11 July through 17 July 1988. Marcelo Filippini won the singles title.
The 1990 Philips Open was a men's tennis tournament played on outdoor clay courts at the Nice Lawn Tennis Club in Nice, France, and was part of the World Series of the 1990 ATP Tour. It was the 19th edition of the tournament and took place from 16 April through 22 April 1990. Unseeded Juan Aguilera won the singles title.
The 1989 Torneo Godó was a men's professional tennis tournament that was played on outdoor clay courts at the Real Club de Tenis Barcelona in Barcelona, Catalonia, Spain that was part of the Championship Series of the 1989 Grand Prix circuit. It was the 37th edition of the tournament and took place from 18 September to 24 September 1989. Unseeded Andrés Gómez won the singles title.
The 1989 Ebel German Open was a men's tennis tournament that was part of the Super Series of the 1989 Nabisco Grand Prix circuit. It was the 80th edition of the event and was played on outdoor clay courts at the Am Rothenbaum in Hamburg, West Germany from 8 May until 15 May 1989. The final was postponed to Monday, 15 May due to rain during the weekend. First-seeded Ivan Lendl won the singles title, his second at the event after 1987, and earned $135,000 first-prize money.
The 1993 Swedish Open was a men's tennis tournament played on outdoor clay courts in Båstad, Sweden that was part of the World Series of the 1993 ATP Tour. It was the 46th edition of the tournament and was held from 5 July until 11 July 1993. Unseeded Horst Skoff won the singles title.
The 1990 Citibank Open was a men's tennis tournament played on outdoor hard courts in Itaparica, Brazil that was part of the World Series category of the 1990 ATP Tour. It was the fifth and last edition of the tournament and took place from 5 November through 11 November 1990. Fifth-seeded Mats Wilander, who entered the draw on a wildcard, won the singles title.
The 1994 Topper Open was a men's tennis tournament held in Montevideo, Uruguay and played on outdoor clay courts. The tournament was part of the World Series circuit of the 1994 ATP Tour. It was the inaugural edition of the tournament and was held from 31 October through 6 November 1994. First-seeded Alberto Berasategui won the singles title.
The 1988 Cedok Open, also known as the Prague Open was a men's tennis tournament played on outdoor clay courts at the I. Czech Lawn Tennis Club in Prague, Czechoslovakia that was part of the 1988 Grand Prix circuit. It was the second edition of the tournament and was held from 8 August until 14 August 1988. Third-seeded Thomas Muster won the singles title.
The 1997 AT&T Challenge was a men's tennis tournament played on outdoor clay courts at the Atlanta Athletic Club in Johns Creek, Georgia in the United States and was part of the World Series of the 1997 ATP Tour. It was the 12th edition of the tournament and was held from April 28 through May 4, 1997. Unseeded Marcelo Filippini won the singles title.
The 1990 Philips Austrian Open, also known as the Austrian Open Kitzbühel, was a men's tennis tournament held on outdoor clay courts at the Kitzbüheler Tennisclub in Kitzbühel, Austria that was part of the ATP World Series of the 1990 ATP Tour. It was the 20th edition of the tournament and was held from 30 July until 5 August 1990. Unseeded Horacio de la Peña won the singles title.
The 1995 Internazionali di Carisbo was a men's tennis tournament played on outdoor clay courts at the Cierrebi Club in Bologna in Italy and was part of the World Series of the 1995 ATP Tour. It was the 11th edition of the tournament and was held from 22 May through 28 May 1995. Unseeded Marcelo Ríos won the singles title.
Marcelo Filippini was the defending champion, but lost in the second round to Nicklas Kulti.
Thomas Muster was the defending champion, but did not compete this year.
Jordi Arrese and Horst Skoff were the defending champions, but competed this year with different partners. Arrese teamed up with Stefano Pescosolido and lost in the quarterfinals to Tomáš Šmíd and Cyril Suk, while Skoff teamed up with Francisco Clavet and lost in the first round to Marcelo Filippini and Marián Vajda.
Marcelo Filippini [1] 
Jordi Arrese / 
Horst Skoff [2] 