| Host City | Sao Paulo |
|---|---|
| Country | |
| Held | 15 – 17 December 1978 |
| Events | 34 |
| Competitors | 98 |
| Countries | 6 |
U19
| Event | Gender | Held | Status | Competitors | Countries |
|---|---|---|---|---|---|
| 100 m, Men | Men | — | Medal | 3 | 2 |
| 200 m, Men | Men | — | Medal | 3 | 3 |
| 400 m, Men | Men | — | Medal | 3 | 2 |
| 800 m, Men | Men | — | Medal | 3 | 2 |
| 1,500 m, Men | Men | — | Medal | 3 | 3 |
| 5,000 m, Men | Men | — | Medal | 3 | 2 |
| 110 m Hurdles, Men | Men | — | Medal | 3 | 2 |
| 400 m Hurdles, Men | Men | — | Medal | 3 | 2 |
| 2,000 m Steeplechase, Men | Men | — | Medal | 3 | 3 |
| 4 x 100 m Relay, Men | Men | — | Medal | 12 | 3 |
| 4 x 400 m Relay, Men | Men | — | Medal | 12 | 3 |
| High Jump, Men | Men | — | Medal | 3 | 2 |
| Pole Vault, Men | Men | — | Medal | 3 | 3 |
| Long Jump, Men | Men | — | Medal | 3 | 2 |
| Triple Jump, Men | Men | — | Medal | 3 | 2 |
| Shot Put, Men | Men | — | Medal | 3 | 2 |
| Discus Throw, Men | Men | — | Medal | 3 | 3 |
| Hammer Throw, Men | Men | — | Medal | 3 | 2 |
| Javelin Throw, Men | Men | — | Medal | 3 | 3 |
| Decathlon, Men | Men | — | Medal | 3 | 2 |
| 100 m, Women | Women | — | Medal | 3 | 2 |
| 200 m, Women | Women | — | Medal | 3 | 2 |
| 400 m, Women | Women | — | Medal | 3 | 2 |
| 800 m, Women | Women | — | Medal | 3 | 3 |
| 1,500 m, Women | Women | — | Medal | 3 | 2 |
| 100 m Hurdles, Women | Women | — | Medal | 3 | 2 |
| 4 x 100 m Relay, Women | Women | — | Medal | 12 | 3 |
| 4 x 400 m Relay, Women | Women | — | Medal | 12 | 3 |
| High Jump, Women | Women | — | Medal | 4 | 4 |
| Long Jump, Women | Women | — | Medal | 3 | 3 |
| Shot Put, Women | Women | — | Medal | 3 | 2 |
| Discus Throw, Women | Women | — | Medal | 3 | 3 |
| Javelin Throw, Women | Women | — | Medal | 3 | 3 |
| Pentathlon, Women | Women | — | Medal | 3 | 2 |
| Pos | Country | 🥇 Gold | 🥈 Silver | 🥉 Bronze | Total | |
|---|---|---|---|---|---|---|
| 1 | Brazil | 13 | 17 | 13 | 43 | |
| 2 | Chile | 9 | 11 | 8 | 28 | |
| 3 | Argentina | 9 | 3 | 4 | 16 | |
| 4 | Peru | 2 | 1 | 4 | 7 | |
| 5 | Colombia | 1 | 2 | 3 | 6 | |
| 6 | Uruguay | 0 | 0 | 3 | 3 | |