They meet on September 18 at The Oval after both playing Bangladesh, who have won just five of their 93 matches since their first official one-day international game in 1986.
South Africa opener Herschelle Gibbs endured a torrid time with the bat in Sri Lanka but his captain Graeme Smith has laid the blame on the whole team.
"The basics let us down. The guys have had a hard look at themselves and are ready to bounce back," he said. "In crunch moments of a game we have got to be more ruthless."
West Indies reached the final of the triangular series with New Zealand and England in July and look a much more cogent side in one-dayers
Brian Lara vowed after the 4-0 Test drubbing to England that he would stay on as captain until at least after this tournament and with youngsters coming through like impressive 20-year-old all rounder Dwayne Bravo, they may surprise a few people.
"We are looking forward to the tournament. We are fit and raring to go," said Bravo. "We know South Africa at this point in time are not playing great cricket and we have to take full advantage."
Group B Fixtures:
September 12 - South Africa v Bangladesh, Edgbaston
September 15 - West Indies v Bangladesh, Rose Bowl
September 18 - South Africa v West Indies, The Oval