The slow kinetics and low efficiency of reprogramming methods to generate human induced pluripotent stem cells (iPSCs) impose major limitations on their utility in biomedical applications. Here we describe a chemical approach that dramatically improves (>200 fold) the efficiency of iPSC generation from human fibroblasts, within seven days of treatment. This will provide a basis for developing safer, more efficient, non-viral methods for reprogramming human somatic cells.