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 l-threonine produced by fermentation with Corynebacterium glutamicum ■■■■■ when used as nutritional additive in feed and water for drinking for all animal species and categories. The product under assessment is l-threonine produced by fermentation with a genetically modified strain of C. glutamicum (■■■■■). The production strain and its recombinant DNA were not detected in the additive. The product l-threonine, manufactured by fermentation with C. glutamicum, ■■■■■ does not give rise to any safety concern with regard to the production strain. l-Threonine produced using C. glutamicum ■■■■■ is considered safe for the target species. The FEEDAP Panel has concerns regarding the safety of the simultaneous oral administration of l-threonine via water for drinking and feed. l-Threonine produced using C. glutamicum ■■■■■ is safe for the consumer. The additive is not a skin or eye irritant and is not a skin sensitiser. Although the workers can be exposed by inhalation, the results of an acute inhalation study showed that risk of adverse effects by inhalation is low. l-Threonine produced using C. glutamicum ■■■■■ is safe for the environment. The product under assessment is considered an efficacious source of the amino acid l-threonine for all animal species. For l-threonine to be as efficacious in ruminants as in non-ruminant species, it requires protection against degradation in the rumen.