In April 2004, increased numbers of hepatitis A were noted in six neighbouring districts in Germany. Exploratory interviews showed that patients had consumed bakery products from company X where two employees had been diagnosed with hepatitis A in February. A case-control study of consumption of products of company X was carried out through telephone interviews. Altogether, 64 cases were identified. Fifty-two cases and 112 controls aged [ges ]16 years were included in the case-control study. In total, 46/52 cases and 37/112 controls had consumed company X products [odds ratio (OR) 15·5, 95% confidence interval (CI) 6·1–39·7]. Of these, 36/46 cases and 16/37 controls had consumed pastries (OR 4·7, 95% CI 1·8–12·3), 25/46 cases and 12/37 controls had consumed filled doughnuts (OR 2·5, 95% CI 1·0–6·1). Sequence analysis of the VP1-2A junction region indicated 100% strain homology between cases and an infected employee of company X. We recommended reinforcement of hygiene precautions, and consideration of a prolongation of compulsory work absence after post-exposure vaccination.