Abstract: Increasing plant salinity tolerance is a focus of research and industry since salinity and yield are of major concern to maximize medicinal and aromatic plants production in arid and semi-arid areas. In this study, we investigate the possible effect of salinity on the seed yield, fixed oil; fatty acids and nutrient content (NPK) of Nigella sativa L an important medicinal plant. Nigella sativa is a widely used medicinal plant throughout the world. It is very popular in various traditional systems of medicine. Plants were subjected to different levels of saline irrigation water, 0.39 (tap water as control), 1.56, 3.13, 4.69 and 6.25 dS m–1. The averages of data were statistically analyzed using one-way analysis of variance (ANOVA-1). Significant values determined according to p values (p<0.05 = significant, p<0.01 = moderate significant and p<0.001 = highly significant). The seed yield, fixed oil and nutrient content (NPK) in general decreased under the various saline treatments. Linoleic, Oleic and Stearic were detected as the major fatty acids of the fixed oil in all the treatments which changed under different salinity levels.