AbstractAqueous micellar solutions of the following surfactants were freeze‐etched and investigated by electron microscopy: eicosyl‐ and docosylsulfate, docosyl‐pyridiniumbromide, hexadecyl‐N‐glycine, sucrose‐monomyristate and ‐palmitate. Micellar weight, aggregation number and critical micellar concentration can be determined by counting the number of micelles per area. Within the investigated range (up to 20 times the cmc) the aggregation number is not influenced by the concentration of the surfactant. The data obtained by electron microscopy are in accordance with those found in the literature.—The size and the shape of the micelles were measured with a particle size analyser. All micelles appeared spherical with a diameter of more than 8 nm. Even if the particles appear too large due to the preparation techniques, the real diameter of the hydrated micelles should always be larger than 6 nm.—This technique is particularly good for the investigation of surfactants with a very low cmc (≤ 10−5molar) in saltfree solutions. Its most interesting aspect is the investigation of systems containing particles of var