Forty pregnant women in each of three trimesters of pregnancy and forty nonpregnant women of comparable age, socioeconomic status and dietary habit have been examined to evaluate the gingival condition and the calculus and debris deposits. The study has shown that: There is a significant increase in the severity of gingivitis during pregnancy; The gingival changes progressively increase during the course of pregnancy; The gingival changes are more marked than the periodontal changes seen during pregnancy (increase in periodontal disease was seen in only a limited number of cases); There was an appreciable increase in the calculus and debris deposits in the pregnant as compared to the nonpregnant women; Increase in the calculus and debris deposits was apparent in all the trimesters of pregnancy; Gingival changes showed a greater correlation with the calculus and the debris index in the pregnant than in the nonpregnant women; The role of the irritant oral deposits either as a precipitating or perpetuating factor in the genesis of gingivitis during pregnancy can not be excluded.