BACKGROUND: Lung cancer is the leading cause of cancer–related deaths worldwide in both men and women. CT scan is the dominant modality in use for lung lesions. Aim of this study was to know relative frequency of different histopathological types of primary lung malignancy & to know their various CT appearances. MATERIAL & METHOD: This prospective study was done in our institute GMERS Medical college & Hospital, Sola, Ahmedabad, Gujarat, India. It included 100 cases of lung lesions, which had undergone CT scan examination from January 2018 to December 2019 & which were later proved to be primary lung malignancy on further workup. RESULTS: In our study, Maximum patients were in the age group 60 – 69 yrs. M:F ratio was around 2:1. Most common histopathological type was Adenocarcinoma followed by Squamous cell carcinoma. Majority of cases of Adenocarcinoma were having peripheral lesion, whereas all cases of Small cell carcinoma & majority of cases of Squamous cell carcinoma were having central lesion. CONCLUSION: Adenocarcinoma is the most common type of primary lung malignancy. Spectrum of CT findings in primary lung malignancy includes peripheral nodule or mass , consolidation, hilar mass, endobronchial nodule, lymphangitis carcinomatosis, hilar/mediastinal lymphadenopathy and pleural effusion. CT remains the important investigation for diagnosis and evaluation of primary lung malignancy with a reasonable degree of diagnostic accuracy.