Background/aim: To evaluate the effects of pelvic floor muscle training (PFMT) on symptoms of overactive bladder (OAB) as well as uroflowmetry parameters and functional bladder capacity. Materials and methods: Fifty-nine female patients with OAB symptoms were included. Patients were assessed by SEAPI-QMM, uroflowmetry, and abdominal ultrasound. A specially designed PFMT program using a Pilates ball was generated for patients. The training period was 1-h sessions twice a week for 6 weeks and aerobic home exercises to be performed at home 4 or 5 times every other day. Following training, subjects were reevaluated for body mass index, SEAPI questionnaire, and uroflowmetry. Results: Initial mean SEAPI score, mean maximum and average flow rates, and mean voided volume were 9.8 ± 7.2, 29.8 ± 16.4 mL/s, 16.3 ± 8.7 mL/s, and 211.6 ± 173.5 mL, respectively. After completion of the training program, SEAPI scores improved significantly to 3.4 ± 6.4 (P < 0.05). Maximum and average flow rate results did not show significant changes, whereas voided volume seemed to have improved in conjunction with patients’ symptom scores (Pearson correlation coefficient: 0.86). Conclusion: According to our results, we think that proper PFMT results in increase of functional bladder capacity as well as improvement in OAB symptoms and can be recommended as first-line therapy or in conjunction with medical therapy in severe cases.