In 1981, at the age of 24, he turned professional. In the 1980s, Rocca struggled to retain a European Tour card and made several trips to the
Qualifying School. He began to make major strides in his career in 1990, which was the first season that he finished high enough on the Order of Merit to retain membership. By 1993, he had risen to sixth in the Order of Merit. His two best seasons were 1995 and 1996, when he finished fourth. He won five titles on the tour, the first of which was the 1993
Open de Lyon and the most prestigious of which was the 1996
Volvo PGA Championship. Rocca is best known for his performance at the
1995 Open Championship. He holed a 60-foot (18-metre) putt on the 18th at
St Andrews to make birdie and force a four-hole playoff with
John Daly but Daly won the playoff by four strokes. Rocca's second-highest finish in a major was a tie for fifth in the
1997 Masters Tournament; he was in the final pairing on Sunday, having begun the final round in second place, nine shots behind 21-year-old
Tiger Woods, and he finished fifteen behind Woods. Rocca was the first Italian to play for Europe in the
Ryder Cup, and remained the only Italian to do so until 2010, when
Francesco Molinari qualified for the Ryder Cup held in Celtic Manor and
Edoardo Molinari was a captain's pick. He appeared in 1993, 1995 and 1997, and had a 6–5–0 win–loss–half record, including 1 win and 2 losses in singles matches. That one singles win came in a crucial match against
Tiger Woods in the 1997 Ryder Cup at
Valderrama, which Rocca won 4 & 2 to help Europe claim the cup. The victory against Woods was one of Woods' first losses in singles play. His 53% winning record in the Cup is one of the best in European team history. During the 1995 Ryder Cup, Rocca made a hole-in-one on Oak Hill's sixth hole, only the third ace in Ryder Cup history. In 1999, Rocca almost qualified for the Ryder Cup again after he won the
West of Ireland Golf Classic. The 2001 European Tour season was the last in which Rocca finished inside the top hundred on the Order of Merit, though he remained exempt through 2006 due to his 1996 Volvo PGA Championship win. He made his
European Seniors Tour debut at the 2007
Sharp Italian Seniors Open, and won his first senior tournament two weeks later at the
Irish Seniors Open. He ended 2008 with a record seven top finishes and ranked ninth in the Order of Merit. His best placing was tied third in the Azores Senior Open. In 2008, Rocca opened his own golf academy, the Costantino Rocca Golf Academy, at Golf Club Gerre Losone in
Switzerland. Rocca played his last European Tour event in 2015 at the
Italian Open, an event he played in 33 times but never won. ==Personal life==