The author reviews in her paper results of 35 epidemiological surveys, including cohort studies, analysis of mortality and case-control studies. All of them focussed on the assessment of risk of neoplastic disease among workers of petroleum refineries and among persons engaged in the fuel distribution. The results yielded by the afore-said surveys, indicate a lower general mortality and mortality from all malignant neoplasms in the populations under study but a higher risk for the occurrence or death from malignant neoplasm of lymphatic and haematopoietic tissue as well as from malignant neoplasm of skin in the refinery workers. Data on risk of death from malignant neoplasm of digestive organs, kidneys, bones, prostate, brain and the central nervous system among the refinery workers and those on risk of death from malignant neoplasm of lymphatic and haematopoietic tissue, kidneys, stomach and lung in persons engaged in the fuel distribution are very often contradictory. It is most probable that confounding factors are responsible for these contradictions.