The Society’s origins date back to 1971, when a Working Group led by I. Szám, D. Müting and V. Bräutigam organized an International Symposium on Ammonia Metabolism. Held in Budapest in May 1972, this first symposium featured Sir Hans Adolf Krebs’ presentation of the newly discovered urea cycle. The well-attended event provided a great opportunity to discuss different aspects of ammonia metabolism and ammonia-related disorders. From that date onwards, the meeting has become a popular triannual event.