The use of cytochrome P450 (P450 or CYP) enzymes as biocatalysts for the production of fine chemicals, including pharmaceuticals, has been of increasing interest, primarily owing to their catalytic diversity and broad substrate range. CYP102A1 (P450 BM3) from Bacillus megaterium integrates an entire monooxygenase system into one polypeptide and represents an appropriate prokaryotic model for industrial applications of mammalian P450 activities. CYP102A1 not only exhibits the highest catalytic activity ever detected in a P450 monooxygenase but also provides a potentially versatile biocatalyst for the production of human P450 metabolites. CYP102A1 can be further engineered to be a drug-metabolizing enzyme, making it a promising candidate to use as a biocatalyst in drug discovery and synthesis.