tEprinomectin (EPN) is a member of the avermectin class of compounds and the onlyanthelmintic registered for goats in Switzerland with a zero milk withdrawal period. Theaim of the present study was to identify the actual efficacy of EPN in an area with a higherdensity of goat enterprises. Forty-three randomly chosen farms from canton Berne wereinvestigated. At least eight goats were investigated on every farm. Conditions for inclusionin the study were the absence of anthelmintic treatment during the previous six weeksand a pooled faecal sample showing a mean faecal egg count (FEC) higher than 600 epgfaeces. Pre- and 14–16 days post-treatment samples were individually collected directlyfrom the rectum. Animals were treated with the recommended dose of EPN (1 mg/kg bodyweight) after taking the pre-treatment samples. Efficacy of EPN was tested with the faecalegg count reduction test (FECRT) and faecal cultures were performed on every farm frompooled faeces samples before and after treatment. Additionally the farmers completed aquestionnaire. None of the gastrointestinal nematode populations of the 43 investigatedfarms were susceptible to EPN at the required level. The mean egg count reduction was40%. None of the typical risk factors, such as production type, stocking rate, animal trafficand quarantine measures showed an association with the level of eprinomectin resistance.It can be concluded with 80% certainty that the prevalence of EPN resistance on goat farmsis at least 95% in canton Berne.