Between 1955 and 1963 millions of people were worldwide vaccinated with polio-vaccines that were contaminated with the simian virus 40 (SV40). This tumor-inducing virus has subsequently been detected in several human tumors. In Austria, polio mass vaccination started in winter 1961/62 with a presumably SV40-free British vaccine. Thus, we hypothesized that the Austrian population should be SV40-free. We used a polymerase chain reaction-based (PCR) method to search for SV40 sequences in DNA that was extracted from 14 giant cell tumors, ten osteosarcomas and eight mesotheliomas. SV40 was easily detected in two bone tumor DNAs from Italy, and one from the USA, and in one SV40 positive cell line. In parallel experiments all Austrian samples tested consistently negative. Our findings support the notion that: 1) polio vaccination is the main source for SV40 in human populations, 2) Austria was not exposed to SV40, and 3) its absence correlates with the low incidence of mesotheliomas in Austria.