The objective of this study was to determine the effects of a triclosan/copolymer dentifrice on plaque formation, gingivitis and gingival bleeding in pregnant subjects. This double-blind clinical study was carried out in 180 women at 3 months of pregnancy. The subjects were stratified into two balanced groups according to their baseline plaque, gingivitis and bleeding scores. Subjects received a thorough dental prophylaxis and were assigned to brush with either a placebo or triclosan dentifrice for five months. They were instructed to brush their teeth as they normally would, twice a day for one minute per brushing. Follow-up examinations after five months of dentifrice use evaluated supragingival plaque, gingivitis and gingival bleeding. After five months, the triclosan dentifrice significantly reduced plaque formation, gingivitis and gingival bleeding by 40.5%, 22.5% and 35.3%, respectively, compared to the placebo group (p<0.05).