Objective: Incontinent women have low rates of care seeking and treatment, some of which may be explained by their beliefs about the causes of their own urine loss. As little is known about these beliefs, our aim was to qualitatively assess what women perceive as the etiology of their urinary incontinence (UI). Methods: In a written survey on urinary symptoms administered to female HMO enrollees aged 30-90 years, incontinent women were asked the open-ended question: "Why do you think you lose urine?" Qualitative analyses of the responses identified themes, which were quantified and organized into major categories. Subjects were assigned multiple themes/categories as indicated. Relationships between major categories and subject/incontinence characteristics were explored. Results: Of the 1458 women with incontinence who completed the survey, 1192 (82%) responded to the openended question. Qualitative analyses identified 23 themes, with 5 themes cited by Ն10% of subjects: pelvic floor/bladder muscles (31%), pregnancy/childbirth (18%), age (14%), exertional triggers (12%), and waiting too long to void (10%). The 23 themes were organized into 5 major categories: pelvic floor/bladder related (53%), uncontrollable factors (23%), part of being female (21%), personal/lifestyle attributes (21%), and don't know (12%). Subjects expressed a range of 1-4 themes/categories. Major categories differed by age, and significant associations were seen between major categories and incontinence severity. Conclusions: Women attribute their UI to a number of causes, which can be condensed into workable themes and categories. By understanding women's beliefs about the etiology of incontinence, clinicians may improve their ability to educate, counsel, and treat women with incontinence.