Objectives: Assessing the experience of screening procedures is crucial for improving the quality and acceptance of colonoscopy in colorectal cancer screening. The aim of the study was to investigate the colonoscopy experience and associated factors among individuals who underwent a colonoscopy in the Screening of Swedish Colons (SCREESCO) study. Methods: Participants in the Screening of Swedish Colons (SCREESCO; n ¼ 7593) randomized clinical trial (colonoscopy vs. faecal immunochemical test (FIT)) were enrolled. The primary outcome was overall colonoscopy experience measured with a study-specific questionnaire. Secondary endpoints were measured using multiple regression analyses with factors that included sex, randomization group, geographical regions, university hospital, complications, sedation, clean bowel, time to cecum, and presence of polyps or cancer. Results: A total of 6572 (87%) individuals responded to the questionnaire. The majority was satisfied with the information, care and treatment. Women reported more worry, discomfort and pain, but also better information, care and treatment compared with men. The FIT group was more worried and perceived more discomfort and pain than the colonoscopy group. Type of hospital (geographical region; university hospital vs. not university hospital) was also a significant predictor for the colonoscopy experience. Conclusions: Although most participants were satisfied with the colonoscopy experience, the study has highlighted areas for improvement. Important factors for colonoscopy experience were gender, randomization group, and type of hospital and therefore crucial to bear in mind when designing screening programs.