Solid-liquid equilibria (SLE), have been measured from 270 K to the boiling temperature of the solvent for nine binary mixtures of 2-methylbenzimidazole (2MBI), with ethers (dipropyl ether, dibutyl ether, dipentyl ether, methyl 1,1-dimethylethyl ether (MTBE), methyl 1, 1-dimethylpropyl ether (MTAE)) and with ketones (pentan-2-one, hexan-2-one, heptan-4-one, 4-methylpentan-2-one) using a dynamic method. The solubility of 2-methylbenzimidazole in ethers and ketones is lower than in alcohols and water and generally decreases with increasing molecular weight of the ether, or ketone. The highest intermolecular solute-solvent interaction is observed for the dipropyl ether and pentan-2-one. Experimental solubility results are compared with values calculated by means of the Wilson, UNIQUAC and NRTL equations utilizing parameters derived from SLE results. The existence of a solid-solid first-order phase transition in solute has been taken into consideration in the solubility calculation. The correlation of the (2-methylbenzimidazole + ketone) solubility data has been obtained with the average root-mean-square deviation of temperature sigma(T) = 1.0 K with every equation used. (C) 2003 Elsevier Science B.V. All rights reserved.