A trial was conducted for 35 days to investigate if replacement of soybean oil (SO) for fish oil (FO) influenced average daily feed intake (ADFI), average daily gain (ADG), final live weight (FLW), feed efficiency (FE), haemato-biochemical indices, carcass traits, cardio-pulmonary morphometry, gut morphology, nutrient digestibility, and fatty acid profile of the broiler chicken. A total of 350, day-old Ross-308 male broilers were distributed in a completely randomized design into five dietary treatment groups designated as FO_0% (diet without FO, i.e., 100% SO), FO_25% (diet containing 25% FO + 75% SO), FO_50% (diet containing 50% FO + 50% SO), FO_75% (diet containing 75% FO + 25% SO), and FO_100% (diet containing 100% FO). Each treatment was replicated seven times containing 10 birds per replicate. Results indicated that complete replacement of SO for FO increased 4.7% FLW, 12.4% ADFI, 3.9% ADG, 16.2% HDL, and 8.6% CP. Although, FO contained 471.1% more ∑LCω-3PUFAs than SO, the FO-supplemented breast meat was enriched with net increment of 45.0% ∑LCω-3PUFAs and 81.0% ∑ω-3: ∑ω-6 at the expense of 7.1% FE and 26.8% MDA. Complete replacement of SO for FO did not compromise net profit. Hence, replacement of SO for FO may be commercially plausible.