The aim of the present study was to evaluate to what extent lifestyle-related variables predict participation for flexible sigmoidoscopy (FS) screening when the compliance is relatively high. During 2001, a randomized sample of 6961 men and women, born between 1946 and 1950, were invited to have a flexible sigmoidoscopy screening examination. Attendees (n = 4111) were asked to fill in a questionnaire focusing on physical activity, body weight, smoking habits and diet. The questionnaire was sent by mail to non-attendees (n = 2628) and a randomized corresponding control group not invited to screening (n = 7000). Sixty-one percent attended for screening. The questionnaire response rate among attendees, non-attendees and controls was 97, 11 and 61%, respectively. Attendees were more physically active (P