Miconazole is an imidazole antifungal agent, developed by Janssen Pharmaceutica, and commonly applied topically (to the skin) or mucus membranes to cure fungal infections. It works by inhibiting the synthesis of ergosterol, a critical component of fungal cell membranes. It can also be used against certain species of Leishmania protozoa (which are a type of unicellular parasite), as these also contain ergosterol in their cell membranes. In addition to its antifungal and antiparasitic actions, it also has some limited antibacterial properties.

Miconazole is also used in Ektachrome film developing (along with surfactants) in the final rinse of the E-6 process, replacing formaldehyde. It is also used in the final rinse additive in Fuji-Hunt's process C41-RA rapid access color negative formulation.