While most current applications of high pressure (HP) are for inactivating deleterious enzymes, there is evidence that high pressure can induce stabilization and activation of some enzymes. Various other strategies have been employed to enhance enzyme stability, including; genetic engineering, immobilization, and operating in non-aqueous media. While each of these strategies has provided varying degrees of stability or activity enhancement, the application of high pressure may be a complementary. synergistic, or an additive enzyme enhancement technique. Over 25 enzymes that have exhibited high pressure stabilization and/or activation were compiled. Each enzyme discussed responds differently to high pressure depending on the pressure range, temperature, source, solvent or media, and substrate. Possible mechanisms for pressure-induced stabilization and activation are discussed and compared with current enzyme enhancement techniques. The compiled evidence of high pressure enzyme enhancement in this review indicates that pressure is an effective reaction parameter with potential for greater utilization in enzyme catalysis. (c) 2009 Elsevier Inc. All rights reserved.