The plaque and gingival condition in 232 Swedish schoolchildren aged 13–14 years has been related to the following predictors: plaque, toothbrushing frequency and technique, bristle stiffness of the toothbrush, smoking habits, use of snuff, social class and sex. Multiple regression analyses have been performed in order to explain the variation of plaque index and of gingival index employing these predictors. Significant predictors of plaque index were toothbrushing frequency, sex (boys), number of cigarettes and social class. The predictors which significantly aggravated gingival inflammation were: plaque, use of snuff and the toothbrushing method modified Bass The slight gingival inflammation due to toothbrushing with the modified Bass’method was not due to inferior plaque removal.