The Robert Koch Institute collects and evaluates data on the prevalence and incidence of HIV, hepatitis C (HCV), hepatitis B (HBV) and syphilis infections among blood and plasma donors in Germany according to Article 22 of the Transfusion Act. The surveillance permits an assessment of the occurrence of infections in the blood donor population and consequently the safety of the collected donations. This report includes data from all blood donation services in Germany for 2001 and 2002. Altogether 5.71 million and 6.63 million donations or blood samples from prospective donors were screened in 2001 and 2002, respectively. The analysis showed a very low incidence of infections with a decreasing trend for HCV infections since 1997 but a slight increase in HIV infections in 2001-2002 compared to 1999-2000. The prevalence of the relevant infections/100,000 donations was 4.7 for HIV, 94.7 for HCV, 159.0 for HBV and 33.4 for syphilis in 2001. The rate of seroconversions/100,000 donations was 0.5 for HIV, 1.6 for HCV, 1.4 for HBV and 1.6 for syphilis in 2001. In 2002 the prevalence/100,000 donations was 7.5 for HIV, 97.4 for HCV, 164.1 for HBV and 31.9 for syphilis. The rate of sero-conversions/100,000 donations in that year was 0.7 for HIV, 1.5 for HCV, 1.2 for HBV and 1.9 for syphilis. The quality of the reported data has improved significantly compared to previous years. Still, some problems remained with the differentiation of the data according to sex, age and interval between donations and the reporting by individual blood donation centres as required by the Transfusion Act.