A cross-sectional coprological survey in the tropical regions of Ada, Akaki, Bereh and Boset, and a retrospective post-mortem investigation were conducted to study the epidemiology of fasciolosis in working donkeys in Ethiopia. Faecal samples from 803 donkeys were collected, and the number of liver flukes recovered from 112 donkeys at post-mortem between 1995 and 2004 were analysed. There was a high prevalence of fasciolosis irrespective of the age of the donkeys. The overall prevalence of the infection was 44.4% in coprologically examined donkeys, and the prevalence in the donkeys examined post-mortem was 41.9%. The infection prevalence was significantly higher in Bereh and Ada regions than in Akaki and Boset regions. Bereh with 72.6% and Boset with 21.5% showed a significantly higher and lower infection prevalence, respectively, than the rest of the regions (P<0.001). There was no significant difference between different age groups of donkeys in the infection prevalence (P>0.05) but infection intensity was significantly higher in donkeys 8 years old and above (P<0.0001). Both Fasciola hepatica and Fasciola gigantica were identified.