The aim of this study is to determine whether staff attitudes towards patients are affected by staff causal attributions. Forty‐eight nurses and doctors were presented with five case histories of patients suffering from lung cancer, liver cirrhosis myocardial infarction, breast lump and cervical cancer. There were two versions of each case: one patient had followed and the other had ignored a relevant health action (e.g. not smoking in the lung cancer patients). Subjects responded to just one version of each case. For all five conditions, staff had significantly more negative attitudes towards patients who had not undertaken a relevant health behaviour compared with patients who had undertaken a relevant health behaviour. A second group of nurses rated it as more likely that this latter group of patients could have prevented their illnesses. The results suggest that information about a patient's health habits prior to illness influence staff attitudes to that patient. Evidence is presented suggesting that the effect of this information is mediated by perceived controllability of the illness, as predicted by an attributional model of helping behaviour.