A randomized controlled study was undertaken to compare the effectiveness of three umbilical cord treatment regimens in controlling neonatal bacterial colonization. The regimens studied included daily application of castile soap, triple dye and silver sulfadiazine. The triple dye and silver sulfadiazine regimens inhibited bacterial colonization. Staphylococcal colonization was inhibited most effectively by triple dye treatment. Group B streptococcal colonization was equally inhibited by triple dye and silver sulfadiazine. Silver sulfadiazine was more effective in controlling colonization with gram-negative microorganisms.