A broad epidemiologic investigation on oral hygiene and gingival health in Greece has been undertaken since 1978. Part of our findings are presented in this study. 1291 male airforce cadet candidates aged 17-22 years were interviewed first concerning brushing habits and gingival bleeding and subsequently using the Russell Index. The mean P. I. score of the group was 0.71, ranging from 0 to 2.13. The highest P. I. was found in the molars (0.82) followed by the anterior teeth and the premolars (0.75 and 0.63, respectively). Statistically significant correlation was found between P. I. and frequency of brushing (P. I. = 0.92 in never brushing, P. I. = 0.69 in twice or more daily brushing). The effect of brushing techniques and bristle stiffness on the P. I. was statistically not significant. As expected the presence of calculus decreased as the frequency of brushing increased. Finally a strong correlation existed between the P. I. and gingival bleeding.