Crops are being genetically engineered to produce a wide variety of drugs, vaccines and other pharmaceutical proteins. Although these crops may open the door to less expensive and more-readily available drugs, there is concern regarding the potential for contamination of human food and livestock feed, as well as environmental harm. The outlook for the production of pharmaceutical crops in California currently appears mixed. To date, 18 federal permits for field trials involving pharmaceutical or industrial proteins have been approved in California. However, the state's farming community and general public have thus far rejected pharmaceutical crop production, and a handful of local governments have recently banned the cultivation of genetically modified crops, including pharmaceutical crops. In light of the many pros and cons, three major approaches ? the precautionary approach, risk analysis and cost-benefit analysis ? could be used to move the debate about pharmaceutical crops forward.