Customers’ behaviour plays an important role in combatting online-banking fraud. This study develops a model of precautionary online behaviour in the domain of online banking, based on protection motivation theory and other behavioural models. The model was tested with questionnaire data of 1200 users of online banking services in the Netherlands. Results from partial-least-squares path-modelling provide support for most hypothesized relationships and show that the model explains high levels of variance for precautionary online behaviour as well as for risk perception. Threat and coping appraisal successfully predict protection motivation of online-banking customers; in particular, response efficacy and self-efficacy are the most important predictors of taking precautions. The outcomes of this study can be used by scholars and information-security professionals to improve security education, training and awareness campaigns directed at safe online banking.