A total of 290 Candida isolates from patients were investigated for in vitro proteinase production. Overall, sixty percent of these strains were found to be proteinase producers. Of the C. albicans strains, 81.4% of the significant isolates in contrast to 19.7% of nonsignificant isolates were proteinase producers, the difference being statistically significant (P less than 0.001). Amongst the different Candida species, the proteinase production was found not only in Candida albicans, but also in C. tropicalis, C. parapsilosis and C. glabrata. Thus this in vitro method of demonstration of proteinase may be a good adjunct to smear and culture examination in identifying pathogenic Candida species from anatomical sites where they can also be present as commensals.