The 1978 South American Championships was a men's Grand Prix tennis circuit tournament held in Buenos Aires, Argentina and played on outdoor clay courts. The event was held from 20 November through 26 November 1978. Fourth-seeded José Luis Clerc won the singles title.
See main article: 1978 South American Championships – Singles. José Luis Clerc defeated Víctor Pecci 6–4, 6–4
Chris Lewis / Van Winitsky defeated José Luis Clerc / Belus Prajoux 6–4, 3–6, 6–0