Objective: This study identified the prevalence of and relationship between mood disorders and multimorbidity in middle-aged and older veterans. Method: Cross-sectional data were obtained from veterans who received primary care services at VA Pittsburgh Healthcare System from January 2007 to December 2011 (n = 34,786). Results: Most veterans had three or more organ systems with chronic disease (95.3%), of which 4.1% had a depressive disorder, 2.5% had an anxiety disorder, and 0.7% had co-occurring depression and anxiety. The odds of having a mood disorder increased with each additional organ system with chronic disease, with odds being the greatest in those with 10 to 13 organ systems with chronic disease. Younger age, female gender, non-married marital status, and having a service connected disability were also significant predictors of having a mood disorder. Discussion: These findings suggest a need to integrate mental health assessment and treatment in chronic health care management for veterans.