Prostate cancer has become a major health problem globally during the last few decades. The incidence rates of this cancer are constantly and rapidly increasing in all the population based cancer registries of India. It is primarily a disease of the elderly. The aim of study was to find out incidence of prostate cancer in Ajmer region and serum PSA relevance in its diagnosis along with various risk factors associated with it. This study was carried out for a period of three years from January 2016 to December 2018 in the department of Pathology, JLN Medical College & Associated Group of Hospitals, Ajmer. Received specimens of prostate were fixed in 10% formalin, processed and stained by Hematoxylin and Eosin followed by histopathological examination. Out of total 508 prostate biopsies received in the department 100 cases were diagnosed as carcinoma of prostate. It was observed that most of the patients were above 65 years of age. Smoking and diet rich in processed meat are high risk factors for carcinoma of prostate. Maximum no. of patient had serum PSA level >10ng/ml, which suggest that risk of prostate cancer is directly related to serum PSA level. The identification of biomarkers such as PSA that are positively correlated with the diagnosis of prostate cancer revolutionized the epidemiology of this disease