A method of preparing cabergoline Form I, comprising forming a solvate including cabergoline and 4-fluorotoluene or 1,3,5-trimethylbenzene and obtaining cabergoline Form I from the solvate. Another aspect of the present invention provides a method for preparing cabergoline Form I comprising dissolving cabergoline in 4-fluorotoluene or 1,3,5-trimethylbenzene and recovering the cabergoline Form 1 polymorph. Cabergoline Form I can then be obtained from the solution, suitably by direct crystallization of Form I or by recovery of a solvate which can be converted to Form I.
