In order to survey the influence of physical activity and micturition habits on urinary leakage (UL) in women before their first pregnancy, a study including 725 women attending nine maternity clinics in the northwest area of Stockholm was performed. During the 36th gestational week the women answered a questionnaire regarding the pre-pregnancy situation regarding UL, micturition habits and physical activity. Thirty-nine percent of the women, mean age of 28 (range 17-43) years, had experienced occasional UL. Of these, the majority (79%) had symptoms of stress urinary leakage and 21% had urge symptoms. Two percent were incontinent according to the definition of the International Continence Society (ICS). In a multivariate analysis age, inability to interrupt the urine flow and high-impact physical activity turned out to be independent risk factors for UL and thus should be observed together with traditional factors concerning UL in nulliparous women.