The rat D2(long) dopamine receptor has been expressed in the fission yeast Schizosaccharomyces pombe at levels of about 1 pmol/mg of protein. The recombinant receptor, analysed in ligand binding experiments, exhibits properties typical of a D2 dopamine receptor and the affinities of antagonists agree with values obtained for the receptor expressed in mammalian systems although the affinities of some antagonists are lower. Substituted benzamide antagonists show lower affinities in the absence of sodium ions whereas clozapine and classical antagonists mostly show higher affinities. Agonist binding is insensitive to the effects of GTP indicating lack of a stable interaction with G-proteins.