Medalists
| Gold | Silver | Bronze |
|---|---|---|
Alejandro Gómez  Venezuela | Lucas Kanieski  Brazil | Julio Galofre  Colombia |
The Men's 400m freestyle event at the 2010 South American Games was held on March 27, with the heats at 10:48 and the Final at 18:15.
| Gold | Silver | Bronze |
|---|---|---|
| Alejandro Gómez Venezuela | Lucas Kanieski Brazil | Julio Galofre Colombia |
| Standing records prior to the 2010 South American Games | ||||
|---|---|---|---|---|
| World record |  Paul Biedermann (GER) | 3:40.07 | Rome, Italy | 26 July 2009 |
| Competition Record | Erwin Maldonado (VEN) | 3:59.57 | Buenos Aires, Argentina | 16 November 2006 |
| South American record | Ricardo Monasterio (VEN) | 3:50.01 | Santo Domingo, Dominican Republic | 14 August 2003 |
| Rank | Heat | Lane | Athlete | Result | Notes |
|---|---|---|---|---|---|
| 1 | 2 | 7 |  Esteban Enderica (ECU) | 4:02.99 | Q |
| 2 | 2 | 3 |  Juan Martin Pereyra (ARG) | 4:03.35 | Q |
| 3 | 2 | 6 |  Sebastián Jahnsen Madico (PER) | 4:03.52 | Q |
| 4 | 2 | 5 | Lucas Kanieski (BRA) | 4:03.60 | Q |
| 5 | 1 | 3 | Daniele Tirabassi (VEN) | 4:03.84 | Q |
| 6 | 1 | 5 | Julio Galofre (COL) | 4:04.00 | Q |
| 7 | 1 | 4 | Esteban Paz (ARG) | 4:04.17 | Q |
| 8 | 1 | 6 | Alejandro Gómez (VEN) | 4:04.30 | Q |
| 9 | 2 | 2 | Mateo de Angulo (COL) | 4:04.58 | |
| 10 | 2 | 4 | Rodrigo Castro (BRA) | 4:05.25 | |
| 11 | 1 | 2 | Ivan Alejandro Ochoa (ECU) | 4:05.59 | |
| 12 | 1 | 7 | Sebastian Arispe Silva (PER) | 4:12.49 | |
| 13 | 2 | 1 |  Alvaro Pfeifer (CHI) | 4:22.72 | |
| 14 | 1 | 1 |  Julio Laurentino (PAR) | 4:41.81 | |
| Rank | Lane | Athlete | Result | Notes |
|---|---|---|---|---|
 | 8 | Alejandro Gómez (VEN) | 3:58.41 | CR |
 | 6 | Lucas Kanieski (BRA) | 13:58.58 | |
 | 7 | Julio Galofre (COL) | 3:58.78 | |
| 4 | 2 | Daniele Tirabassi (VEN) | 3:59.63 | |
| 5 | 5 | Juan Martin Pereyra (ARG) | 4:01.51 | |
| 6 | 1 | Esteban Paz (ARG) | 4:01.57 | |
| 7 | 4 | Esteban Enderica (ECU) | 4:03.22 | |
| 8 | 3 | Sebastián Jahnsen Madico (PER) | 4:04.65 | |