In the present study, a field experiment was conducted for two consecutive seasons (2016/2017 and 2017/2018). The effects of organic and inorganic fertilization on growth, seed yield, seed fixed oil yield, and fatty acid profile of garden cress (Lepidium sativum L.) were investigated under conditions of Khartoum State, Sudan. In each season, the experiment was laid out in a randomized complete block design with four replications. Four fertilizer treatments were used; these were chicken manure at a rate of 11.9 tonha −1 , NPK (15:15:15) at two rates, 476 kgha −1 (NPK1), 952 kgha −1 (NPK2) as well as the control. Morphometric parameters, yield components, seed fixed oil content (%), seed fixed oil yield (tonha −1), and fatty acids profile were measured. Means were separated using the least significant difference at p ≤ 0.05 and at p ≤ 0.01. The difference between chicken manure, NPK1, and NPK2 was not significant (p ≤ 0.05) in both seasons, for plant height and 1000-seed weight. However, it was significant (p > 0.05) with chicken manure in both seasons for the number of leaves (831.7, 684), the number of branches (144.8, 128.5), fresh weight (57.74, 61.25), and dry weight (6, 7.7). The NPK2 treatment significantly (p ≤ 0.05) increased the number of capsules (339.5, 308 tonha −1), seed yield (5.51, 4.8 tonha −1), seed fixed oil content (25.65%, 25%), and seed fixed oil yield (1.4, 1.1 tonha 1) compared to the control in both seasons. The oil profile was affected by all fertilizer treatments. Acoordingly, it can be concluded that using fertilizer is recommended for improvement of growth, seed yield, and oil yield, and quality of L. sativum.