Abstract Following a request from the European Commission, the 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 Amoklor (ammonium chloride) as a zootechnical additive for ruminants, cats and dogs. A concentration of 10,000 mg Amoklor/kg complete feed is considered as safe for ruminants when administered during a restricted feeding period (< 3 months). For longer periods of administration, a concentration of 5,000 mg Amoklor/kg is considered safe. For cats, 5,000 mg Amoklor/kg in the complete diet can be considered safe for an unlimited period. Data for dogs are limited to three short‐term studies with small numbers of animals. The adverse effect seen in one study would suggest that the dose for dogs should be limited to 5,000 mg Amoklor/kg. As both ions of ammonium chloride will be rapidly excreted predominantly via the kidney, no increase in the endogenous concentration of these ions in tissues and products is expected. The use of Amoklor in animal nutrition does not raise any concerns for consumer safety. Amoklor should be considered as an irritant to skin, eyes, the digestive and respiratory tract, and a dermal and respiratory sensitiser. The use of Amoklor in feedingstuffs at the maximum level of 10,000 mg/kg does not pose a risk for the environment. Supplementation with 10,000 mg Amoklor/kg feed for ruminants reduces urinary pH and the formation of urinary calculi, and is efficacious on the prevention of milk fever (hypocalcaemia) at early lactation in old high‐yielding dairy cows. Supplementation of feed for cats and dogs with 5,000 mg Amoklor/kg results in a decrease in urinary pH and is expected to protect against the formation of urinary calculi.