Evidence suggests that dentists' efforts to encourage their patients to stop tobacco use can significantly decrease tobacco-related morbidity and mortality. This study identified attitudes and counseling practices of 1116 Iowa dentists and compared results of a subgroup (N = 55) surveyed in both 1983 and 1989 to note changes in their tobacco-related attitudes and practices. Although only 9% of the dentists from the statewide survey felt counseling their patients on tobacco use was inappropriate, 56% reported they did not routinely ask their new patients about tobacco use. With some frequency 90% of the dentists discussed negative health effects of tobacco, whereas only 64% advised their smokers to quit. In addition, fewer than half made special efforts with pregnant patients or those at high risk for heart disease. The vast majority reported seldom if ever using intervention tools such as pamphlets or referral to cessation programs. Data from the subgroup surveyed in 1983 and 1989 indicated few substantial changes in attitudes and counseling practices. Substantial discrepancies exist between dentists' attitudes and counseling practices. Well-designed programs are needed to help dentists select and implement appropriate interventions.