From raw and pasteurized milk and cheese, human, bovine and pig faeces, human nose and throat swabs, 553 pure cultures were isolated and tested by a cross-streak technique on agar. From the same sources, but without isolation and purification of the cultures, 510 samples were also tested by spotting individual colonies with a test-organism culture of Streptococcus agalactiae. A further 8016 samples were tested after enrichment by a quick assay using Str. cremoris as the test organism. The samples examined failed to reveal antibiotic producing streptococci with the exception of some strains of Str. lactis which produced nisin.