To describe and evaluate the Catquest self-assessment questionnaire for cataract patients. Thirty-five Swedish departments of ophthalmology. The Catquest is designed to be used by cataract surgeons for continuous quality control regarding appropriateness and outcome of surgery. It is administered before and after cataract surgery. The questionnaire focuses on visual disabilities in daily life, activity level, cataract symptoms, and degree of independence. The results are interpreted using a benefit matrix that credits not only a decrease in visual disabilities and cataract symptoms but also an improvement or a maintenance of a preoperative activity level. The questionnaire was used by consecutive patients having surgery during March 1995 at the participating surgical units. A full range of responses was given to all questions. A strong relationship was found between patients' responses to questions about visual disabilities in daily life and their general opinion about vision (P < .001). The answers showed a high stability when test-retest reliability was evaluated and a high internal consistency when different questions about visual disabilities were compared (P < .001). The answers from cataract patients before surgery were significantly different from those of a control group that did not have cataract (P < .0001). The Catquest had high validity and reliability when used as a disease-specific instrument testing visual disabilities in patients having cataract extraction.