The death of a pet can be a significant stressor for some people and is a known risk factor for depression. The Pet Bereavement Questionnaire (PBQ) was developed to fill the need for a brief, acceptable, well-validated instrument for use in studies of the psychological impact of losing a pet. Initial results suggest that the PBQ has good internal reliability (Cronbach's alpha = 0.87), as well as good construct validity, with three distinct factors reflecting grief anger and guilt. Grief was found to correlate strongly with pet attachment. The anger and guilt scales, however, correlated with depressive symptoms. The PBQ discriminated between individuals seeking support after pet loss (who would be expected to show higher levels of bereavement) and those who simply acknowledge the recent loss of a pet. We suggest that future research into pet bereavement use this new questionnaire so that the results of different studies can be compared, normative scores can be developed and researchers in this area can use a single instrument with established construct validity. In particular, we hope the PBQ will be used in treatment outcome research to identify high-risk individuals and test the effectiveness of both existing and novel interventions. Moreover, the PBQ could also be used in clinical settings, such as tertiary care veterinary hospitals, to identify pet owners in need of clinical support services.