【Objective】 To investigate the clinical characteristics and prognostic factors of small cell carcinoma of bladder (SCCB), and to explore the efficacy of neoadjuvant therapy. 【Methods】 Clinical information of 47 SCCB patients were retrospectively collected, and the clinical and pathological features were compared with those of urothelial carcinoma (UBC). The prognostic factors and efficacy of neoadjuvant therapy were also investigated. 【Results】 SCCB had higher baseline tumor staging, and was more likely to invade the muscle (100%) and metastasize distantly (21.3%). The overall survival was poor (median: 13.1 months, 1-year survival rate: 53.7%, 5-year overall survival rate: 15.4%). Tumor T staging was a risk factor for SCCB, while neoadjuvant therapy was an independent protective factor that significantly reduced the risk of recurrence and metastasis (HR: 0.189, 95%CI: 0.051-0.697, P=0.012) and death (HR: 0.177, 95%CI: 0.045-0.698, P=0.013), and significantly improved disease-free survival and overall survival. In addition, compared with neoadjuvant chemotherapy alone, neoadjuvant chemotherapy combined with immunotherapy could improve the pathological complete response rate. 【Conclusion】 SCCB is highly malignant and prone to metastasis, and has a poor prognosis. Neoadjuvant therapy combined with radical cystectomy is recommended as the first-line treatment.