The aim of this study was to evaluate the causes of hospitalization of female patients in a Pulmonary Department. We studied the female patients that had been hospitalized in our clinic during the last four years (1996-1999). We grouped our female patients in pulmonary disease-categories, studied the group number of the hospitalized females for the last four years and for each year, separately. We did not take under consideration those patients who had been admitted to our department for the same cause. Subsequently, 1055 female patients were found to be hospitalized in our clinic for the last four years. Comparing the whole number of patients being hospitalized, we did not found any statistical difference. Comparing the group-number of individuals, we did not prove any statistical difference in the annual incidence of each disease. In conclusion, the most important causes of female-patients hospitalization were COPD (25%), pulmonary infection (14%), bronchial asthma (13%), lung cancer (12%) and pneumonia (9%). Other pulmonary diseases as tuberculosis, sarcoidosis, collagen diseases of the lung, represent a smaller percentage. At the same time, 2084 male patients were hospitalized in our department. Out of them, 29.7% were suffering from lung cancer, 29.2% from COPD, 7.9% from pneumonia, 5.4% from respiratory infection and 3.74% from asthma. There was a statistical significant difference in the incidence of COPD, lung cancer and bronchial asthma between males and females that were hospitalized for that time period (p<0,001). Pneumon 2001, 14 (1): 74-80