Current recommendations for periodontal health maintenance emphasize toothbrushing, flossing and periodic dental checkups. The purposes of this study were to examine (1) the effects of these practices on periodontal health and (2) the relationships of demographic and socioeconomic variables with these behaviors and with periodontal health. Adults (n = 319) in the Detroit, Michigan tri-county area were asked how frequently they performed the 3 preventive behaviors. Levels of plaque, gingivitis, calculus, and periodontal attachment were then assessed during in-home dental examinations. There were no statistically significant differences in these health measures between those with acceptable and unacceptable brushing behavior. About 20% of the subjects reported acceptable flossing behavior, and these individuals had significantly less plaque and calculus than other participants. Over 3/4 of subjects reported having a dental checkup at least 1 x a year, and these persons were found to have significantly less plaque, gingivitis, and calculus compared to less frequent attenders. Acceptable brushing behavior was not associated with any particular demographic or socio-economic characteristic, while differences in acceptable flossing behavior were found among age groups. Frequencies of yearly dental checkups varied significantly within every demographic and socioeconomic characteristic.