The declining diversity of agricultural production and food supplies worldwide may have important implications for global diets. The primary objective of this review is to assess the nature and magnitude of the associations of agricultural biodiversity with diet quality and anthropometric outcomes in low- and middle-income countries. A comprehensive review of 5 databases using a priori exclusion criteria and application of a systematic, qualitative analysis to the findings of identified studies revealed that agricultural biodiversity has a small but consistent association with more diverse household- and individual-level diets, although the magnitude of this association varies with the extent of existing diversification of farms. Greater on-farm crop species richness is also associated with small, positive increments in young child linear stature. Agricultural diversification may contribute to diversified diets through both subsistence- and income-generating pathways and may be an important strategy for improving diets and nutrition outcomes in low- and middle-income countries. Six research priorities for future studies of the influence of agricultural biodiversity on nutrition outcomes are identified based on gaps in the research literature.