A fast yeast-transformation technique has been developed by adding thio compounds to alkali-ion based protocols and incubating at 45°C. This procedure is especially recommended for cells from stationary phase at a density up to 2.5×108 cells/ml. It involves only one step for the preparation and transformation of competent cells within 30 min. The yield was more than 104 transformants/μg plasmid DNA. This protocol is easy to scale up for many DNA samples and is also applicable for yeast cells from different types of storages.