Farmyard manure is considered as a source of plant nutrient supply, but high N loss and low N use efficiency are often serious challenges facing this source of nutrient. It is supposed that a combination of manure with inorganic fertilizers can reduce this problem. A two year experiment was conducted in 2004-2005 at Mazandran province of Iran in order to study the effects of manure, inorganic nitrogen and combination of manure-inorganic nitrogen on N loss and yield of winter oilseed rape (Brassica napus L.) under rainfed conditions. Treatments included 0, 50, 100 and 150 kg N ha^-1 urea (F₀, F₅₀, F₁₀₀, F₁₅₀), 100 kg N ha^-1 urea + 50 kg N ha^-1 manure (F₁₀₀M₅₀), 50 kg N ha^-1 urea + 100 kg N ha^-1 manure (F₅₀M₁₀₀), 150 kg N ha^-1 manure (M₁₅₀). The highest grain yield (3 ton ha^-1) was obtained with the 150 kg N ha^-1 as urea treatment in both years. Grain yield in M₁₅₀ treatment was significantly lower (p<0.05) than F₁₅₀. However F₁₀₀M₅₀ and F₅₀M₁₀₀ resulted in similar yields compared with F₁₅₀ treatment. Results also showed that F₁₀₀M₅₀ and F₅₀M₁₀₀ treatments decreased N loss (4 and 3 kg N ha^-1 year^-1, respectively) compared to application of manure alone (33.5 kg N ha^-1 year^-1) and F₁₅₀ (36 kg N ha^-1 year^-1). Overall, it could be conducted that F₁₀₀M₅₀ is the best treatment because it produced similar grain yield compared to F₁₅₀ while resulted in lower N loss as well.