In 2008, a mixed pair of a Roseate Tern Sterna dougallii and a hybrid Roseate X Common Tern S. hirundo nested at an artificial peninsula in the port of Zeebrugge, Belgium. Although more Roseate Terns (at least 9 individuals) and hybrids (at least 3) have visited the large colony of Common Terns, only one pair nested here before. The female Roseate Tern was ringed in 2004 as a chick at Lady’s Island Lake, Wexford, Ireland. At first sight and based on sound, her partner appeared to be a Common Tern, but close examination of a photo revealed that it had several Roseate Tern characteristics. The two-egg clutch was completed 13 June 2008 and the first chick hatched 4 July. Both eggs and chicks showed characteristics intermediate between Common and Roseate Tern. The pair probably fledged one chick. Hybridisation between Roseate and Common Tern is described in literature and also successful breeding of their hybrid offspring has been mentioned. This is to our knowledge, however, the first documented report of a mixed pair Roseate Tern and hybrid Roseate X Common Tern in Europe.