Fungicides on soybeans provided growers an effective management strategy for foliar diseases, especially soybean rust. However, many questions about fungicide and how common practices affect fungicide efficacy are still unresolved. One possible cultural practice that may affect fungicide efficacy is plant population. Higher plant populations may lead to a denser canopy, which may lead to a more conducive microenvironment for certain plant diseases. The denser canopy also may reduce the penetration of fungicides to the lower canopy. The objective of this study was to evaluate the efficacy of fungicide in four different soybean plant populations.