Feather plucking, or the removal by a parrot of its own feathers, is thought to be one of the most common behaviour presentations in veterinary practices that treat avian patients. However, its aetiology is poorly understood. The aims of this study were to estimate the prevalence of feather plucking within the population of African grey parrots (Psittacus erithacus erithacus and Psittacus erithacus timneh) and cockatoos (Cacatua spp.) registered with 9 veterinary practices in the United Kingdom (UK) and to explore the association between frequently hypothesised risk factors and feather plucking in these species. A questionnaire was sent to the owners of 400 African grey parrots and 310 cockatoos registered with 9 UK veterinary practices. Returned questionnaires from 137 African grey parrots and 92 cockatoos were analysed, of which 39.4% of African grey parrots and 42.4% of cockatoos had exhibited feather-plucking behaviour at some point in their lifetime. Multivariable logistic regression modelling demonstrated that increasing hours of sleep and length of ownership were significantly associated (P < 0.05) with feather plucking in African grey parrots. Pet shop origin, cage location against ≥1 wall and ≥1 vacation taken by owners each year were significantly associated (P < 0.05) with feather plucking in cockatoos. The high prevalence of feather plucking in these commonly kept pets highlights this problem as a welfare concern, whereas the risk factor analysis challenges many frequently cited hypotheses regarding its aetiology. Further research is required to explore whether there is a causal relationship between the significant risk factors identified in this study and feather-plucking behaviour.