Incidence of lung cancer is high in the male population of the German Democratic Republic: 0,005--4,63 per thousand annualy in the age groups 25 years and above. Therefore, efforts to improve early detection are mandatory. Possibilities and effectivity of screening for lung cancer are discussed. Only mass X-ray examination and exfoliative cytology have up to now gained practical importance. Most roentgenological studies performed so far show methodological weaknesses. Based upon recent studies of screening of high risk groups in the USA and in the GDR, it is suggested that this method applied in short intervals may be effective. Cytological screening of risk groups demands high costs and cannot be implemented on a broad base. Ways of optimization of cost-benefit ratio in roentgenological screening are discussed.