Samples of stimulated whole saliva were obtained from ninety-four 12-14-year-old school children living in inner London to evaluate if there was a correlation between Streptococcus mutans counts in saliva with plaque amount, gingival inflammation and caries experience. S. mutans counts were obtained by a dip-slide method (Dentocult 'Strip Mutans') in which the count was expressed as 0, 1, 2, 3, or 4 based on visual estimation of the colony density. There was no association between counts' of S. mutans in saliva with plaque amount and gingival inflammation. However, there was a significant trend of increased decayed, missing, filled surfaces (DMFS) with increasing S. mutans counts.