A group of 232 schoolchildren aged 13-14 years in the Municipality of Huddinge, on the outskirts of Stockholm, were examined in order to study the effects of smoking and oral use of snuff in relation to oral health. Of the schoolchildren 21.5% smoked regularly. Snuff was taken regularly by 11% of the boys, but none of the girls. Snuff was present in the oral cavity for an average of 3.5 hours every day. The variable "number of cigarettes" was found to be a significant (p less than 0.01) predictor to the dependent variable "plaque" after controlling for the predictors "frequency of tooth-brushing" and "sex". Snuff usage showed a strongly significant correlation to gingival index after controlling for plaque. The result showed that use of snuff may influence on the gingival tissue directly whereas smoking affects plaque accumulation.