The methylotrophic yeast Hansenula polymorpha belongs to a limited number of non-Saccharomyces yeast species used as hosts for heterologous gene expression. It has successfully been applied for the production of hormones, antigens and enzymes. The system excells by mitotically stable recombinant strains, high productivity and faithful processing of the produced polypeptides. The favourable characteristics of this microorganism for protein production at an industrial scale are described in the following article focusing on some recent representative examples.