Preparation of cabergoline

A method of preparing cabergoline Form I, comprising forming a solvate including cabergoline and a p-disubstituted benzene of formula (A) 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 p-disubstituted benzene or 1,3,5-trimethylbenzene and recovering the cabergoline Form I polymorph, suitably by direct crystallization of Form I or by recovery of a solvate which can be converted to Form I. Another aspect of the present invention provides a novel cabergoline polymorph designated cabergoline Form FB and a method of preparing said polymorph by dissolving or forming a solvate of cabergoline in fluorobenzene and recovering cabergoline Form FB.