Introduction & Objective: Lung cancer is the most common cause of cancer death among the population of most countries in the world. In Hamadan as a region with significant population in Iran, the epidemiologic studies have not previously done. Therefore ,this study was carried out to evaluate the frequency of histopathological types of primary pulmonary malignant neoplasms in patients admitted to Hamadan educational hospitals from 2005 to 2015.

Materials & Methods: This research is a cross sectional study. In this study, 263 cases(225 males and 38 females) out of 429 pathology samples reported to be lung cancers  were entered into the study. These data were collected at Be’asat, Shahid Beheshti and Razi pathology laboratory centers. The data were analyzed by STATA software, c², t test and ANOVA.

Results: The results show that in Hamadan contrary to the world statistics, 44.87% of patients had squamous cell carcinoma, 25,1%had small cell lung cancer, 14.8% had adenocarcinoma and 15.2% had other types of carcinoma. 85.5% of the samples  were related to  males and 14.45% related to females.

Conclusion: This study shows that during 10 years in Hamadan province in opposite of universal studies bronchogenic lung cancer tumor was squamous cell carcinoma. Moreover ,tumors incidence in males are more than women.

 (Sci J Hamadan Univ Med Sci 2016; 23 (1):17-24)