Veterinarians are more likely to experience mood disorders and suicide than other occupational groups (Fritschi, Morrison, Shirangi & Day, 2009; Platt, Hawton, Simkin, & Mellanby, 2010). The performance of euthanasia has been implicated as contributing determinately to the prevalence of suicide risk and psychological distress in veterinarians (Bartram & Baldwin, 2008, 2010). In contrast, the application of psychological approaches would suggest a possible protective role for euthanasia administration. This paper is the first to investigate the association between euthanasia-administration frequency and depressed mood and suicide risk. A cross-sectional survey sampled 540 Australia-registered veterinarians (63.8% women), ranging in age from 23 to 74. Results revealed that the administration of objectionable euthanasia (i.e., euthanasia that the veterinarian disagreed with) was not related to our mental health variables. In contrast, overall euthanasia frequency had a weak positive linear relationship with depression. Moreover, overall euthanasia frequency moderated the impact of depression on suicide risk. The nature of this moderation suggested that average frequency per week of performing euthanasia attenuated the relationship between depressed mood and suicide risk. The implications of these findings and directions for further research are discussed.