Background: The majority of antineoplastic agents have been found to show mutagenic, teratogenic and carcinogenic potential. Biological effects of long-term contact with low levels of cytostatic drugs are not well known. The results of many studies are ambiguous, which might be associated with varying levels of exposure in different hospitals. Material and Methods: About 100 physicians and nurses employed in the Department of Pediatric Bone Marrow Transplantation, Hematology and Oncology, Wroclaw Medical University, are exposed to cytostatic drugs. Over the last 15 years, nine cases of cancer occured, which may result from occupational exposure to antineoplastic agents. The most severely affected professional group are physicians, among whom 5 cases of cancer were identified. Conclusions: Clinical situation of the Department requires an immediate action, including genetic studies, which are already under way. Moreover, all of the safety rules applicable when working with antineoplastic agents should be applied.