We validated a new 7-item overactive bladder symptom score.Normal subjects and consecutive patients with lower urinary tract symptoms with or without overactive bladder were recruited and classified into 3 groups based on their response to the question on an intake questionnaire, "Do you ever experience a sudden urge to urinate that makes you want to stop what you are doing and rush to a bathroom?" Subjects completed the written questionnaire in privacy on 2 occasions.There were 84 subjects, including 33 men and 51 women, with a median age of 62 years (range 18 to 88). Of the subjects 33 (39%) had overactive bladder, 30 (36%) had lower urinary tract symptoms without overactive bladder and 21 (25%) were normal. There was a high level of internal consistency at visits 1 and 2 (Cronbach's alpha = 0.83 and 0.80, respectively, p <0.001). For test-retest reliability Spearman's rank order correlation coefficients for the items were r = 0.72 to 0.79 (p <0.001). A strong correlation was also observed between the total 7-item scores at visits 1 and 2 for each diagnostic subgroup, and for all participants (r = 0.86, p <0.001). Discriminant validity was established by determining significant differences in responses among the 3 subgroups at each administration (p <0.01).The overactive bladder symptom score is a valid instrument that assesses all aspects of overactive bladder. It may be used as a symptom score.