Plastics are widespread, persistent environmental pollutants. The incidence and types of plastic in the nests of northern gannets (Sula bassana) were quantified at two colonies in eastern Newfoundland. Overall, 97% of the nests sampled had plastic incorporated in them, and there was no significant difference in the incidence of nests with plastic in the two colonies. Most nests (78%) contained fishing gear (rope, line, netting); plastic package strapping (12%), bags or sheets (7%), and hard plastic (3%), including shotgun shell casings, and lobster pot tags, occurred in many nests. A diversity of other plastic items was also found. A small percentage of adult and chick mortality resulted from entanglement in synthetic materials incorporated in nests. Present levels of the occurrence of plastic in nests at other gannetries should be assessed, because the relative abundances of different types of debris in nests could be used as mega- and meso-scale indicators of synthetic materials in different oceanographic regions.