Various antimicrobial solutions for topical use on burn wounds tested, in vitro with a newly described wet disc assay, for their activity against bacterial isolates from patients with burns. The antimicrobial activity of triple antibiotic solution was shown to reside in the neomycin component. The activity of 2.5% mafenide hydrochloride solution was equal to that of 4% mafenide HCl and could be used clinically with significant savings and perhaps, fewer side effects. Chlorhexidine gluconate had broad antimicrobial activity in an 0.05% solution in water; however, dissolving the active ingredient in saline nullified its activity significantly. The wet disc assay appears to be a useful means by which to assess the efficacy of solutions for topical use.