In 2019 a fledged Peregrine Falcon was detected in the harbour of Den Helder (province of Noord-Holland), where a nestbox had been erected in 2003. In 2020, the pair raised 4 chicks, followed by 3 chicks in 2021 (from 4 eggs). Prey remains and larders were regularly checked from January 2020 onwards, and the nestbox was also cleaned frequently. Altogether 421 prey remains were collected, i.e. 216 in the breeding season (15 April-15 July) and 205 in the remaining months of the year. The prey list comprised 45 species ranging in body mass between 18 (Linnet) and 530 g (Oystercatcher). The five main prey species in summer weighed 63.7% of all summer prey, in winter slightly less (57.5%). The five most important prey species in summer (by biomass) were Feral Pigeon, Bar-tailed Godwit, Collared Dove, Knot and Redshank. In winter the top five in biomass consisted of Knot, Feral Pigeon, Grey Plover, Bar-tailed Godwit and Woodcock. In summer, Peregrines captured 53.2% of prey biomass over land (including the town of Den Helder), compared to only 31.0% in winter. In the non breeding season the falcons more often hunted small waders in the Wadden Sea, especially Knot, Dunlin, Redshank and Grey Plover. Mean prey weight during the breeding season was slightly less (161 g) than in the non-breeding season (172 g), perhaps indicating the larger share of males in hunting during the breeding season.