The increasing use of alternative therapies that rely on organically grown foods has renewed interest in the relationship between agricultural methods and food quality. The purpose of this article is to review the literature produced over the last 50 years comparing the nutritional quality of organic with conventional crops. Whereas few studies have been conducted, there is a trend in the data indicating higher nutrient content in organically grown crops. This phenomenon is possibly due to a higher water content in conventional crops, which causes nutrient dilution. For individual nutrients, existing studies show that organic fertilization practices produce crops with higher levels of ascorbic acid, lower levels of nitrate, and improved protein quality compared with conventionally grown crops. Although a theoretical rationale exists for possible effects of herbicides on nutrient content, few studies have examined the effects of these or other pesticides. Animal studies showed better growth and reproduction in animals fed organically grown feed compared with those fed conventionally grown feed. Further research is required to confirm the trends seen in the existing data and to clarify the exact relationships between agricultural management and nutritional quality.