PURPOSE: Urinary storage symptoms are the most common and most bothersome urinary symptoms. Many studies on the relation between body weight and urinary symptoms have focused on urinary incontinence in women. We evaluated the association of obesity with urinary storage symptoms in a population based study of men and women age 18 to 79 years old. MATERIALS AND METHODS: Questionnaires were mailed to 6,000 adults randomly identified from the Finnish Population Register. Self-reported height and weight were used to calculate body mass index. Urinary frequency, nocturia, urgency, stress urinary incontinence and urgency urinary incontinence were assessed using validated instruments. Multivariate logistic regression analyses (adjusted for age, comorbidity and medications, and sociodemographic, lifestyle and reproductive factors) were performed to evaluate associations between body mass index and each symptom. RESULTS: Of the 6,000 individuals approached 3,727 participated (62.4% response, 53.7% women). In men and women obesity was associated with nocturia (adjusted OR 2.0, 95% CI 1.2-3.3 for men; OR 2.4, 95% CI 1.5-3.8 for women) but not with urgency (adjusted OR 1.2, 95% CI 0.7-2.3 for men; OR 1.2, 95% CI 0.7-2.1 for women). In men obesity was also associated with urinary frequency (OR 2.0, 95% CI 1.0-3.9), and in women it was associated with stress urinary incontinence (OR 1.9, 95% CI 1.2-3.0) and urgency urinary incontinence (OR 3.0, 95% CI 1.2-7.4). However, the number of men with stress urinary incontinence or urgency urinary incontinence was insufficient for precise analyses. CONCLUSIONS: This study extends previous research by providing symptom specific associations between obesity and urinary storage symptoms in a population based sample of men and women. Obesity impacts individual urinary storage symptoms differently and these associations may be influenced by gender.