During about 3 years 100 cases of recurrent staphylococcal furunculosis were studied with reference to phage-types of strains from lesions, nares, perineum and groins in relation to possible contamination sources. Phage group II staphylococci were found in 58% of the cases. In about half of the patients the same phage type was found in the nares as in the lesion but in the perineum and/or groins in only 14%. In two thirds of these cases the strains belonged to phage group II. Phage group II strains were isolated mainly from patients after supposed contamination outside hospital, while these strains were not dominating in patients probably infected in hospital. An epidemiological study revealed that recurrent furunculosis mostly has its origin outside hospital. Phage typing of lesion and nares strains is essential for the epidemiological analysis of recurrent furunculosis.