Choo, T. M., Martin, R. A., Savard, M. E. and Blackwell, B. 2014. Effects of planting date and earliness on deoxynivalenol contamination in barley under natural epidemic conditions. Can. J. Plant Sci. 94: 1363-1371. Fusarium head blight, principally caused by Fusarium graminearum Schwabe, is a destructive disease of barley in many countries and it can result in mycotoxin contamination such as deoxynivalenol (DON) in the grain. An integrated management strategy is needed to mitigate the level of DON contamination in barley. Therefore, a study was initiated to determine if early planting and early-heading cultivars can be used to avoid severe DON contamination under natural epidemic conditions in the Maritimes. Twelve six-row barley cultivars were planted in a split-plot design with two planting dates (early vs. late) as main-plot units and cultivars as sub-plot units at the Harrington Research Farm in Prince Edward Island in 2007, 2008, 2010, 2011, and 2012. Grain samples from all experimental plots were contaminated with DON and one contained as high as 23.1 mg kg^-1. Early planting frequently resulted in less DON contamination and higher yield than late planting. Days to heading was positively correlated with DON concentration only at late planting in 2007. The results of this study suggest that six-row barley should be planted early in the Maritimes to avoid a high level of DON contamination and a reduction in grain yield, and that use of early-heading cultivars may not be effective at reducing DON contamination while retaining high yield.