Lung cancer is a malignant epithelial carcinoma and the most common type of cancer in Croatia in incidence and mortality. One of the leading causes of lung cancer is smoking, followed by air quality of the area in which an individual lives. Until its closing in 2008, air analyses in the proximity of the INA plant at Mlaka (Rijeka) have shown high concentrations of NO2 and SO2. Concentrations of these compounds exceed from 2000 to 2008 the limit values that are in accordance with the European Union standards. Additionally, it has been noted that the concentration of floating particles (PM10) in Rijeka area exceeds the limit value over several periods until 2008. Incidence and mortality rates show that the incidence rate of lung cancer in the Primorje- Gorski Kotar County (78.2 per 100,000 inhabitants in 2015) is higher than the average rate for the Republic of Croatia (71.7 per 100,000 inhabitants in 2015). Also, the mortality rate is higher in the Primorje- Gorski Kotar County (71 per 100 000 inhabitants) than the average for the Republic of Croatia (65.8 per 100 000 inhabitants). The aim of this paper is to analyze and compare incidence and mortality rates of lung cancer and associate it with the aforementioned air pollution that encompasses the area of Rijeka i.e. Mlaka until 2008 in areas with poorer air quality. For purposes of the analysis, the data from the cancer registry and the data from the Public Health Institute of the Primorje–Gorski Kotar County, as well as data from the Croatian Institute of Public Health that were combined in air quality reports in the County have been used.