Patients with fresh full-thickness burn wounds were randomly assigned to receive wound treatment with daily applications of either I per cent silver sulfadiazine plus 0·2 per cent chlorhexidine digluconate cream (Silvazine) or 1 per cent silver sulfadiazine (Flamazine). Fifty-four patients treated with Silvazine were comparable to 67 treated with Flamazine with respect to extent and distribution of burn, age and all aspects of wound and associated treatment. Overall incidence of wound bacterial colonization was less in the Silvazine treated patients (65 per cent versus 88 per cent; P = 0·002). With Silvazine, wound colonization by Staphylococcus aureus was less (41 per cent versus 64 per cent; P = 0·01). Clinical wound infection with Staph. aureus developed in one Silvazine treated patient and five Flamazine treated patients (P = 0·16). Colonization by and infection due to all other organisms did not differ in the two groups. The incidence of graft failure was similar with both agents. In future increasing the concentration of chlorhexidine digluconate above 0·2 per cent might produce an improved prophylactic effect against Gram negative bacteria reported by other authors using the combined agent in in vitro and clinical trials. Silvazine was effective in reducing the incidence of Staph. aureus burn wound colonization without fostering supervening opportunistic infection.