Following a request from the European Commission, the EFSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of lemongrass oil obtained from the aerial parts of Cymbopogon flexuosus (Nees ex Steud.) Will. Watson when used as a sensory additive for all animal species. The FEEDAP Panel concluded that lemongrass oil is safe up to the maximum proposed use levels in complete feed of 125 mg/kg for salmonids; 100 mg/kg for sows and horses; 75 mg/kg for veal calves (milk replacer), cattle for fattening, dairy cows, sheep and goats; and 50 mg/kg for dogs and ornamental fish. For the other species, the calculated safe concentrations in complete feed were 41 mg/kg for chickens for fattening, 61 mg/kg for laying hens, 55 mg/kg for turkeys for fattening, 74 mg/kg for piglets, 88 mg/kg for pigs for fattening, 65 mg/kg for rabbits and 33 mg/kg for cats. These conclusions were extrapolated to other physiologically related species. For any other species, the additive is safe at 33 mg/kg complete feed. The use of lemongrass oil in water for drinking for poultry, pigs, calves and rabbit is safe provided that the total daily intake does not exceed the daily amount considered safe when consumed via feed. No concerns for consumers and the environment were identified following the use of the additive up to the highest safe use level in feed. The essential oil under assessment should be considered as an irritant to skin and eyes and as a dermal and respiratory sensitiser. Since the aerial parts of C. flexuosus and its preparations were recognised to flavour food and its function in feed would be essentially the same as that in food, no further demonstration of efficacy was considered necessary.