21188 Background: Analysis of the cases of malignant lung tumors of young people (<34 yrs, born in 1963–2004) and diagnosed in 1997–2004 was made using the materials of the database of cancer registers of Volyn (V), Ivano-Frankivsk (IF), Lviv (L), Rivne (R), Ternopil (T) and Chernivtsi (C) regions. The population of young people <34 yrs of this region - 4.2 million/year. Results: Among 7541 cases of cancer in the six regions of the Western Ukraine malignant tumors of the lungs were diagnosed in 102 cases (1.4%). This pathology was registered in males in 57 cases, and in females in 45. The number of males with tumors of the lungs prevailed in V, IF, L, T. The number of young males and females with such pathology during the said period was the same - 11 cases in each gender group - in R. The youngest among the 102 individuals from the above said six regions were a boy aged 6 and a girl aged 16 from R. Combination with other tumors was observed in three females (C49, C53, C58) and one male (C81). In C among 766 cases of malignant tumors in young people <34 years lung cancer were detected in 5 (0.7%). Among 959 cases of cancer such tumors of the lungs were detected in 8 (0.8%) in V. Among the young people <34 years this pathology was detected in 14 (1.2%) in IF out of all 1156 cases of malignant tumors, in T - 947 tumor - 15 cases (1.6%). Among the six above regions in L there have been detected 2465 cases of malignant tumors, of which lung cancer were diagnosed in 38 - 1.5%. The highest frequency of occurrence of this pathology was registered in R (1.8%) - 22 cases in 1248 cases of malignant tumors. Conclusions: Fluctuation of frequency of this pathology in all these regions in various years during the investigated period had a wave-like character. As each of these regions is characterized by different geographic and climatic conditions, physical and chemical factors, exhausts of industrial enterprises, the study of frequency of malignant tumors in young people will permit to evaluated more objectively contribution of hereditary factor in the development of this pathology. The perspectives of further research in this field lie in the study of the role of genetic predisposition to the occurrence and development of malignant tumors in each patient, taking into account ecological zone of residence, occupational hazards and harmful habits. No significant financial relationships to disclose.