Using a variety of in vitro techniques, it is now possible to isolate a selected gene sequence from any source and introduce it into any major crop plant.  Millions of hectares of such genetically modified (GM) or transgenic plants are already being grown commercially, mostly in North America.  To date, the most widely grown GM crops (soybean and maize) are those with modified agronomic traits (herbicide or insect tolerance); the products from these commodity crops are now included in a wide range of processed foods.  This review describes the methods used to generate these GM crops and then discusses the range of modified food products that can be generated using this new technology.  Such products include those with altered protein, starch or oil quality, as well as examples of improved micronutrient or vitamin content.  Much of this work, particularly that aiming to develop food with specific health benefits, is still at the experimental stage, but there is no doubt that many GM foodstuffs, with an increasing variety of qualitative changes, will reach the market in the coming years.  The rate at which such products are developed commercially depends to a large extent on the public reaction to a technology still poorly understood by most consumers.