The use of 1,3-substituted imidazolium salts of the formula I in which R1 and R3 independently of one another are an organic radical having 1 to 20 C atoms, R2, R4, and R5 independently of one another are an H atom or an organic radical having 1 to 20 C atoms, it also being possible for R4 and R5 together to form an aliphatic or aromatic ring, X is an anion having a pKb of less than 13 (measured at 25° C., 1 bar in water or dimethyl sulfoxide), and n is 1, 2 or 3, with the exception as imidazolium salts of 1-ethyl-2,3-dimethylimidazolium acetate and 1-ethyl-2,3-dimethylimidazolium acetate-acetic acid complex, as latent catalysts for curing compositions comprising epoxy compounds.