Bulb yield and storability of onions (cv. N-2-4-1) were studied against deficit irrigation approach during rabi season of 2012 and 2013 at Instructional Farm of the Department of Irrigation and Drainage Engineering, Dr. Annasaheb Shinde College of Agricultural Engineering, Mahatma Phule Krishi Vidyapeeth, Rahuri. The experiment was carried out in Randomized Block Design (RBD) with 27 treatments and two replications based on different combinations of the quantity of water stress during different crop growth stages. Water applied per irrigation and soil moisture contents before and after irrigation was monitored throughout the season, while onion bulbs were harvested at the end of the season and weighed. Yields and storage losses are higher with less water stress and reduced with an increase in water stress. The highest yield of onion was obtained with a no stress treatment (T1) and it was at par with treatment (T4) which is 20% stress at the bulb development stage. Losses due to rotting, sprouting, and physiological weight loss were found higher in irrigated treatments. After six months of storage (from 1st week of May to 1st week of October), the maximum cumulative weight loss (49.09%) was recorded in onions irrigated at maximum stress treatment (T27), while the minimum (38.21%) was recorded in T4 treatment which is 20% stress during bulb development stage.