An investigation was carried out to study the effect of FYM as source of N, on the growth and yield of onion (Allium cepa L.) cv. Nasik Red under irrigated condition at Horticultural Research Station Hidkal Dam during kharif 2011. Significantly highest bulb yield of (221.62 q/ha) and yield contributing characters of onion likes bulb diameter and fresh bulb weight (6.43 cm and 98.13 g, respectively) was obtained when 75% N through FYM + 25% N through chemical fertilizer (T3) was applied. However, T1, T2 and T5 were also equally superior to T3. Significantly highest plant height (55.64 and 54.58 cm at 90 and 115 DAT respectively), number of leaves (8.3, 9.3, 10.2 and 9.7 at 30, 60 90 and 115 DAT respectively) and neck thickness (1.78, 1.07 and 0.95 cm at 60, 90 and 115 DAT respectively), as well as highest dry matter content in leaves, bulb and total dry matter production per plant (2.98, 19.63 and 22.61 g, respectively) was recorded when plant received 75% N through FYM + 25% N through chemical fertilizer (T3). Thus, 50 and 75% of recommended N can be substituted through application of FYM.