The preferably optically clear, transparent or translucent micromulsion contains from 20 to 60 percent by weight water; from 3 to 20 percent by weight of an oil phase, which contains hydrophobic oil that is liquid at 25.degree. C. and optionally dissolved lipophilic materials, and from 20 to 60 percent by weight of an emulsifier mixture. The emulsifier mixture contains at least one first emulsifier, which is an ethoxylated castor oil and/or an ethoxylated hydrogenated castor oil, and at least one second emulsifier with an NRU.sub.50 value greater than 110 .mu.g/ml. The microemulsion is usable as a cosmetic, dermatological or pharmaceutical preparation, especially as an agent for hair treatment.