Tumors arise by disrupting the normal regulation of cell growth control mechanisms, they are represented by irregular and progressive cell growth. Tumors can be malignant (malignant) and benign (benign). They differ in the aggressiveness of cell growth. Lung cancers can be primary, they can start growing in any part of the lung, or they can arise as a result of metastasis of tumor cells, in which case they are called secondary. Primary tumors are most often malignant. The most common symptoms of cancer are: shortness of breath, prolonged cough, chest pain, fatigue, loss of appetite, nausea and weight loss. Symptoms appear due to local irritations, pressure on the bronchi and other anatomical structures. The most significant factors that favor the development of lung cancer are: cigarette smoking, passive smoking and the action of various carcinogenic substances in the work environment such as: asbestos fibers, soot, tar, radon and ionizing radiation. Numerous non-invasive and invasive methods are used in the diagnosis of lung tumors whose task is to make a correct diagnosis and monitor the course of the disease. The most common radiological methods for diagnosing lung tumors are chest X-rays, computed tomography of the thorax, PET / CT, and magnetic resonance imaging. Of the invasive methods, we use bronchoscopy, which is performed under general or local anesthesia, where a flexible bronchoscope enters through the mouth or nose and this allows the discovery of pathological changes from which a sample is then taken for cytological and histological analysis. Transthoracic puncture is done when the tumor is out of sight of the bronchoscope, and is done under the control of CT or exceptionally ultrasound. Carcinomas are histologically divided into small cell carcinomas and non-small cell carcinomas. The group of non-small cell tumors includes the following subtypes: adenocarcinoma, squamous cell carcinoma and large cell carcinoma. Small cell carcinoma is characterized by aggressive growth and a higher rate of metastasis. Cancer cells grow and spread in different ways, so they are treated differently. Treatment and early detection of lung cancer is complicated by the fact that the symptoms of the disease appear only at an advanced stage. Small cell carcinomas spread rapidly and metastasize early, so they are not treated surgically but by radiotherapy and chemotherapy. Non-small cell carcinoma in case it is localized or only locally expanded is treated surgically, which most often involves lobectomy. Longer survival after surgery is recorded after the introduction of chemotherapy before or after surgery. However, due to the fact that lung cancers are in the early stages, they are most often asymptomatic and are often diagnosed at an advanced stage. In this case, they are treated conservatively. Conservative treatment methods available to us today are chemotherapy, radiotherapy, targeted and immunotherapy. Of the newer therapeutic methods, stereotactic radiosurgery (SBRT) has also shown good results. A retrospective study was performed, which included patients who in the period from 23.11.2019. to 06/10/2021 at the Clinical Department of Radiology, Sušak locality, Clinical Hospital Center Rijeka, a lung tumor was diagnosed by CT. The data we used in this study were taken from the ISSA and IBIS hospital information systems. The aim of the study was to examine the prevalence of patients with lung cancer with respect to sex, age, histological type of cancer and the method of obtaining a sample for cytological and histological analysis. The most important conclusions that emerged from this study were that the incidence of lung cancer was slightly higher in men, that it most often affects the elderly, and that the most common histological type of tumor is adenocarcinoma.