A simple, inexpensive microbiological assay for objective measurement of denture hygiene has been devised. Small individual filter paper discs were applied to the fitting surface of dentures for 20 seconds, eluted in phosphate buffered saline and bacterial counts on blood agar plates performed on the eluate. There was a strong positive correlation between denture cleanliness (graded on a scale of 0 to 4) and both total anaerobic count (r = 0.829; P < 0.001) and total aerobic count (r = 0.786; P < 0.001) following logarithmic transformation. Yeasts in the eluted disc specimens could be used as an aid to diagnose oral candidiasis. The method provided an objective measure of denture hygiene among elderly patients in longstay hospitals and daycare community places. It may be applicable to audit studies following implementation of new oral health care policies.