Purpose: We compared the importance of patient age and gender relative to the intensity of baseline symptoms of overactive bladder in the therapeutic response to the muscarinic receptor antagonist tolterodine. Materials and Methods: Data from an open label, observational study of 2,250 patients with overactive bladder treated for 12 weeks with tolterodine were analyzed for alterations in frequency, urgency and urge incontinence, and for global efficacy and tolerability using logistic regression analysis, stratifying for gender, age, baseline symptom intensity and tolterodine dose. Results: Gender or tolterodine dose were not consistently associated with altered treatment efficacy. Greater age was associated with a slight but statistically significant decrease in treatment efficacy. Patients with great baseline symptom intensity had greater treatment associated improvement but a lesser chance to become symptom-free. Even with a large number of patients no statistically significant gender or age associated alterations in the tolerability of tolterodine treatment were detected. Conclusions: The extent of the therapeutic response to tolterodine is largely determined by the extent of baseline symptoms. While gender does not affect the efficacy or tolerability of tolterodine in a clinically relevant manner, advanced age is associated with a slight decrease in efficacy but not in tolerability.