OBJECTIVES:To determine in women with clinically stable chronic lung disease (CLD) and healthy women; (1) prevalence of urinary incontinence; (2) risk factors for urinary incontinence; (3) effects of a standard course of specialised physiotherapy treatment (PT) in women with CLD. DESIGN:Prospective prevalence study; PT study in CLD subgroup. SETTING:Tertiary metropolitan public hospital. PARTICIPANTS:Women with cystic fibrosis (CF, n=38), chronic obstructive pulmonary disease (COPD, n=27) and 69 healthy women without CLD. PT study - 10 women with CLD. INTERVENTIONS:Five continence PT sessions over 3 months. MAIN OUTCOME MEASURES:Prevalence and impact of incontinence (questionnaire), number of leakage episodes (7-day accident diary), pelvic floor muscle function (ultrasound imaging) and quality of life (King's Health Questionnaire). RESULTS:The majority of women in all three groups reported episodes of incontinence (CF 71%; COPD 70%; healthy women 55%). Compared to age-matched healthy controls, women with CF reported more episodes of incontinence (P=0.006) and more commonly reported stress incontinence (P=0.001). A logistic regression model revealed that women with CLD were twice as likely to develop incontinence than healthy women (P=0.05). Women with COPD reported significantly more 'bother' with incontinence than age-matched women with incontinence. There was a significant reduction in incontinence episodes following treatment, which was maintained after three months. CONCLUSIONS:The presence of CLD is an independent predictor of incontinence in women. In older women this is associated with more distress than in age-matched peers without CLD. Larger treatment studies are indicated for women with CLD and incontinence.