Objective: This study aimed to compare the clinical features, prognosis, and survival rates of patients with small cell carcinoma of the lung or extrapulmonary origin to get a new perspective for customized treatment strategies for both diseases. Material and Methods: We evaluated 254 patients with either small cell lung carcinoma (SCLC) or extrapulmonary small cell carcinoma (EPSCC) who were diagnosed and treated at Trakya University Hospital, Department of Medical Oncology from 2010 to 2020. We also compared these groups regarding their disease control rate, disease-free survival (DFS) in the limited disease (LD) stage, radiological progression-free survival (PFS), and overall survival (OS). Results: The SCLC group showed a male predominance, which was statistically significant. There was a statistically significant difference was observed concerning bone and brain metastases in the SCLC group. The median DFS was 16.7 and 9.4 months in the EPSCC and the SCLC groups with LD, respectively. Additionally, PFS and OS were similar between LD and extensive disease (ED) stage patients, respectively. Several factors like the presence of liver metastasis at the time of diagnosis, patients >60 years, poor performance status, and high lactate dehydrogenase (LDH) levels were associated with poor OS in ED patients. Conclusion: Although a significant difference was observed in DFS between both groups in LD patients, there was no significant difference between OS and PFS in LD and ED patients of SCLC and EPSCC groups, respectively. Moreover, the presence of liver metastasis and high LDH levels were a few factors that negatively affected the OS of patients.