A field experiment was carried out in the Experimental Farm of Assiut University during 2010-2011 and 2011- 2012 seasons. The study aimed to obtain the best yield of Nigella sativa L. seeds and volatile oil per experimental  unit(1× 1.5 m )by using three plant densities ; low ( 20-plant∕ plot) , medium(40-plant ∕ plot) and high ( 80-plant ∕ plot ) and four fertilizer treatments; control (without fertilization) , mineral fertilizer (NPK 70kg/fed.) , cattle manure (CM 30 m³∕ fed.) and foliar fertilization TOP STAR (NPK+TE 2g∕ l). The results showed that low plant density increased both of seed yield and volatile oil production per plant followed with medium and high plant density with significant differences in most cases. Using of mineral fertilizer (NPK) considerably increased both of seed yield and volatile oil per Plant compared with unfertilized plants (control). Although same increases resulted with cattle manure and foliar fertilizer the differences were not always significant. During the first and second seasons As yield per feddan, results showed that both of high plant density and mineral NPK fertilizer resulted in considerable higher production in both of seed and volatile oil yields compared with the other treatments. The interaction among plant densities and the different fertilizer treatments showed that the highest yield of both seeds and volatile oil per feddan, generally, resulted with the high plant density accompanied with mineral NPK fertilization.