This study examined the influence of lifetime accumulated trauma on late-life mental health in a sample of 1,216 older adults, 65–94 years old, residing in New Zealand. Multiple regression analyses indicated that accumulated trauma predicted both depression and anxiety in this sample. The hypothesis that avoidance of memories and situations surrounding prior trauma mediates relationships between cumulative trauma and depression and anxiety was supported. Avoidance of prior traumatic memories and situations explained 49% of the variance between accumulated trauma and depression and 46% of the variance between accumulated trauma and anxiety. Results also suggest that traumatic experiences during young adulthood and middle age are stronger predictors of anxiety and depression among older adults than trauma experienced in childhood and adolescence.