The Richibucto Estuary, located in the southern Gulf of St. Lawrence, is rearing habitat for a population of white perch (Morone americana), as well as for young-of-the-year striped bass (M. saxatilis) which immigrate from the nearby Miramichi Estuary. In this study we compared the diet of white perch caught in the Richibucto Estuary to a previously published account of the diet of young-of-the-year striped bass in the Miramichi Estuary. One hundred and fifteen white perch of 26–168 mm total length (TL) were collected from the Richibucto Estuary between 25 June and 10 October 1998 by onshore beach seining at 10 sites. Eighty-nine percent of their stomachs contained food. Sand shrimp (Crangon septemspinosa) were found in 69–79% of stomachs and constituted at least 80% of total dietary weight for white perch = 50 mm TL. Copepods (cyclopoids and the large calanoid Eurytemora sp.) constituted almost all of the diet of small white perch (<50 mm TL) found in low salinity but in higher salinities (11–20‰) mysids and sand shrimp were also important components of the diet. Polychaete worms and amphipods (Gammarus sp.) were minor constituents of the diet of both size categories of white perch. The diet of young-of-the-year white perch in the Richibucto Estuary was found to be similar to that of young-of-the-year striped bass studied previously in the Miramichi Estuary.