This study aimed to evaluate the treatment patterns and long-term efficacy of onabotulinumtoxinA injections in a clinical setting. This single-center retrospective study was conducted on patients with refractory overactive bladder (OAB) aged 18 years or older who received onabotulinumtoxinA 100 IU administered between April 2012 and May 2022. The primary endpoint was the treatment pattern, including the retreatment rate and OAB medication prescription pattern. The duration and effectiveness of onabotulinumtoxinA treatment were analyzed using the overactive bladder symptom score and voiding diaries. A total of 216 patients were enrolled in this study, and the overall patient satisfaction rate was 55.1%. After the first injection, 19.9% received a second treatment, and 6.1% received three or more injections. The median duration until the second injection was 10.7 months. Among the patients, 51.4% resumed OAB medications after 2.96 months. The presence of urodynamic detrusor overactivity was observed only in female patients (odds ratio, 23.65; 95% CI, 1.84 to 304.40), which was associated with a good response. In contrast to clinical trials, the degree of improvement and retreatment rate did not meet expectations. Our findings provide valuable insights into the effectiveness of onabotulinumtoxinA injections in patients with refractory OAB symptoms in real-world practice.