Few crops have shown adaptability for growers in the inland Pacific Northwest to include in small grain cereal cropping systems. Rapeseed (Brassica napus L.) crops have long been included in cropping systems in this region, albeit on a small number of acres. In 1992, researchers at the University of Idaho initiated a breeding program to develop adapted cultivars of oriental and brown mustard (B. juncea L.) and recently have released two cultivars. Canadian researchers have developed canola-quality B. juncea mustards that might have potential for this region. However, no research has been conducted to determine optimum nitrogen management, seeding rates, or planting dates for B. juncea. This study investigates these characters to assist regional growers in maximizing crop productivity and seed quality of B. juncea crops. In 2004, four cultivars (Pacific Gold, Kodiak, Arid, and Dahinda) were evaluated at two seeding dates in each of two locations. Five nitrogen rates were applied and three seeding rates were examined for each cultivar. Data collected included plant stand counts, flower start dates, plant heights at maturity, yield, oil content and seed size. Yield potential of the four cultivars differed, with Pacific Gold producing the highest yield. At the highest nitrogen levels, the locally developed mustard-type cultivars (Pacific Gold and Kodiak) had greater yields than the canola-quality cultivars (Arid and Dahinda). Oil content of the seeds decreased as nitrogen rate was increased. The early planting date averaged higher yields, most likely because they had a longer period before flowering. Planting later resulted in lower oil contents and a higher stand count. The medium seeding rate yielded significantly higher than the low rate, but was not significantly different from the highest rate. Implications of these results are discussed in relation to potential for the new B. juncea crops in Pacific Northwest cropping systems.