Objective Neuromodulation has emerged as an effective therapeutic option for treatment of OAB in children. However, to our knowledge, no study has yet evaluated the results of neuromodulation on a sessionby- session basis. The aim of this study was to evaluate the rate of complete response of overactive bladder (OAB) symptoms for each session of transcutaneous electrical stimulation (TENS), in a protocol of 20 sessions of therapy. Method This is a prospective study of the improvement of LUTS in children with isolated OAB. Included in this study were children over the age of 4 years who complained of urinary urgency, had bell-or-tower-shaped uroflowmetry patterns, and post-void residual <10% of expected capacity for their age and/or less than 20 mL. No patient was treated with an anticholinergic. Children were excluded with lower urinary tract symptoms (LUTS) secondary to urinary tract abnormalities. All patients underwent parasacral transcutaneous neurostimulation (TENS). The development of symptoms was observed right before each session using a visual analog scale (VAS) in which 0 means the absence of improvement and 10 represents maximum improvement of symptoms. Results We noted a complete resolution of symptoms (urgency, urge incontinence, frequency, and holding maneuvers) in some patients starting after the third session. In the 10th and 20th (last) sessions, 12 (17.4%) and 38 (55.1%) patients reported a complete resolution of symptoms. After complete resolution, 12 (17.4%) patients reported that their symptoms worsened to a minimum level of 40% improvement, but this was temporary and all returned to 100% improvement. Children who showed an improvement level greater than 50% in the fifth treatment session were 4.18 (p = 0.007) times more likely to have success in the last treatment session. Conclusion We found that a patient can experience complete symptom resolution as quickly as following the third session of TENS. The complete response rate progressively increases with the number of sessions, slowly until the 12th session and more rapidly after that. When symptom improvement of at least 50% is reported in the fifth session, there is a higher chance that the patient will have full resolution of symptoms at the end of treatment.