Methylotrophic yeasts can obtain all of their required carbon and energy from methanol, a promising feedstock for biotechnological and chemical processes and a potential replacement for coal and petroleum. When these yeast cells are cultured in the presence of methanol, the enzymes involved in methanol metabolism are massively produced, indicating that the gene promoters of these enzymes are strong methanol-inducible promoters. Using these promoters, high-level heterologous gene expression systems have been developed in several methylotrophic yeast strains, including Pichia pastoris, Hansenula polymorpha, Pichia methanolica and Candida boidinii. In the present minireview we describe recent insights into the molecular basis of methanol-inducible gene expression in C. boidinii. In addition, the utility of C. boidinii gene expression systems for the production of various enzymes is also reviewed.