Purpose: The aim of this study was to investigate the tolerability of postoperative early intravesical chemotherapy session after transurethral resection of the bladder tumor (TUR-B) according to the different anesthesia types. Methods: The study was conducted between February 2017 and June 2020. Patients who were given intravesical mitomycin (MMC) 40 mg after TUR-B were included. Patients’ risk categories (low, medium, and high) were determined according to the European Association of Urology (EAU) risk stratification system based on the tumor number, size (Results: A total of 232 consecutive patients who received intravesical MMC were included. Sociodemographic characteristics of group S (n = 113) and group G (n = 119) were similar (p < 0.05). There were no significant differences in tumor size, number of tumors, concomitant CIS, and T stage in both groups (p > 0.05). High-grade tumors were higher in group S (23.9 vs. 11%; p = 0.008). Requirement of analgesic (53.9 vs. 91.5%; p = 0.00) and termination of therapy p = 0.00) and p = 0.00) were significantly lower in group S. The mean instillation time (108.05 ± 19.40 vs. 85.67 ± 24.66 min; p = 0.00) was found significantly higher for group S. In group G, mean VAS1–4 scores were significantly higher than in group S (p < 0.05). Linear correlation analyses showed that the VAS score is correlated with the instillation time (p < 0.05). The rates of minor (I–III) (7 vs. 8%; p = 0.706) and major (IV–V) (0.9 vs. 1.6%; p = 0.590) complications were similar in both groups. Conclusion: The patients’ tolerability of intravesical MMC treatment can be improved by spinal anesthesia. It provides longer instillation time and less pain during intravesical chemotherapy.