The aim of the present study was to assess for the first time the dissemination of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli in the wild animal ecosystem in Switzerland. Fecal samples of 84 red deer, 64 roe deer, 64 chamois, and 27 ibex were investigated. One sample from a roe deer tested positive for ESBL-producing E. coli. The isolate harboured blaCTX-M-1 and tested negative for both blaTEM and blaSHV. Based on these results low occurrence of ESBL-producing Enterobacteriaceae in the wild animal ecosystem in Switzerland must currently be postulated. Further studies are necessary to assess future trends.