BACKGROUND: Sacral nerve stimulation (SNS) approved for use in North America since 1997 despite the fact that the concept of using SNS to treat patients with voiding dysfunction discussed first almost 50 years ago. AIM: The objectives of the study were to assess the effectiveness of SNS the short and long term for patients with overactive bladder (OAB) dysfunction and its relation to age, gender, and causes. PATIENTS AND METHODS: This is a clinical prospective study that involved 50 cases (32 females and 18 males) with OAB. It was carried out at Ibn Sina Hospital, and the neurosciences hospital in Baghdad/Iraq from April 2015 to April 2018. All the patients were assessed preoperatively and certain inclusion criteria were used. The patients went through the 2 stage implantations of the Medtronic InterStim®. The patients were assessed at 6 months (short term) and 2 years (long term) postoperatively. RESULTS: The results of our patients were analyzed with respect to age, gender, causes of OAB, and post-operative complications. We found that younger age patients, female patients, and patients with neurogenic causes of OAB showed a better response in both the short- and long-term follow-up. CONCLUSION: Considerable progress has been made in the surgical management of OAB. Proper selection of patients is the key to the success of SNS, and female patients have better results compared to male patients. Furthermore, younger patients and patients with neurogenic causes did better than older patients and patients with idiopathic causes. SNS is a safe minimally invasive surgery with a low complication rate, and the 2 stages procedure has better results than the percutaneous nerve evaluation.