Reports of inmate-officer assaults from a prison population of 1,000 males and covering an 18-month period were analysed in order to test the hypothesis that staff who either have little prison work experience or are relatively young might be more likely to be the victims of assault. No significant difference was found between the ages of assaulted and non-assaulted officers, but the difference between the two groups in number of months' prison work experience proved statistically significant. In addition, no correlation was found between the age of the inmate and age of the officer he assaulted, or between the age of the inmate and the experience of the victim officer. The implications and possible reasons for the finding that more experienced officers are less likely to be assaulted are discussed.