A 23-year-old Turkish woman was admitted with an infection of the left thumb. The clinical picture was typical for cutaneous anthrax. Microbiological tests confirmed the diagnosis 'infection by Bacillus anthracis'. She recovered when treated with penicillin, although later tests revealed that the bacteria were resistant to this antibiotic. The patient became infected in Belgium as a result of wounding herself on the teeth of an illegally slaughtered sheep, which had possibly become infected in the pasture. Recognising the characteristic clinical picture of cutaneous anthrax is essential for prompt treatment and a favourable prognosis.