&NA;Four hundred seventeen asymptomatic patients with an average age of 52 years underwent screening flexible fiberoptic sigmoidoscopy. Seventy‐three polyps were detected in 52 patients with a 17.5 per cent detection rate. Half were above 25 cm and one‐third were greater than 1.0 cm in size.Biannual follow‐up of these patients is planned to determine the efficacy of this screening procedure combined with removal of all polyps in preventing the development of colorectal cancer.