In the period 1971-73 various extra enteral habitats have been examined for the occurrence of resistant E. coli. Of 172 isolates of E. coli from retail butcher's meat products 9.9% were resistant and 3.5% R+ E. coli. Of 203 isolates of E. coli from bakery products 7.9% were resistant and 3.5% R+ E. coli. Of 52 isolates of E. coli from freshly killed carcases of chickens 40.4% contained weak non-transferable monoresistance against sulphonamides (Table I). Of 92 isolates of E. coli from seawater receiving human sewage 15.2% were resistant and 4.4% R+ E. coli (Table III). All but one samples of sewage and crude sludge contained resistant E. coli of which 11% harboured R factors (Table II). Of 117 Salmonella isolates from human sewage 11.1% were resistant and in 4.2% resistance were transferable (Table VI). Quantitative examinations of untreated and treated sewage did not indicate any selective reduction of resistant E. coli compared to sensitive (Table IV). However, more di- and multiresistant E. coli were found in sewage than in seawater (Fig. 1). The food hygienic implications of resistant E. coli are discussed.