We examined the potential for contact sensitization of miconazole nitrate and croconazole hydrochloride and the cross-reaction between them in guinea pigs by the maximization test of Magnusson and Kligman. Contact sensitivity was induced by croconazole hydrochloride in 5 out of 7 animals which, after being injected with 5% croconazole hydrochloride, underwent a closed patch with 25% croconazole hydrochloride. Contact sensitivity was not induced by miconazole nitrate. The 5 animals sensitized to croconazole hydrochloride were tested with 8 other imidazole antifungals and positive reactions were observed to oxiconazole nitrate in 2 of the 5 animals. This response may be a cross-reaction.