Introduction:Anxiety, depression, and pain are major problems among veterans, despite the availability of standard medical options within the Veterans Health Administration. Complementary and alternative approaches for these symptoms have been shown to be appealing to veterans. One such complementary and alternative approach is mindfulness-based stress reduction (MBSR), a brief course that teaches mindfulness meditation with demonstrated benefits for mood disorders and pain. Methods:We prospectively collected data on MBSR’s effectiveness among 79 veterans at an urban Veterans Health Administration medical facility. The MBSR course had 9 weekly sessions that included seated and walking meditations, gentle yoga, body scans, and discussions of pain, stress, and mindfulness. Pre-MBSR and post-MBSR questionnaires investigating pain, anxiety, depression, suicidal ideation, and physical and mental health functioning were obtained and compared for individuals. We also conducted a mediation analysis to determine whether changes in mindfulness were related to changes in the other outcomes. Results:Significant reductions in anxiety, depression, and suicidal ideation were observed after MBSR training. Mental health functioning scores were improved. Also, mindfulness interacted with other outcomes such that increases in mindfulness were related to improvements in anxiety, depression, and mental health functionality. Pain intensity and physical health functionality did not show improvements. Discussion:This naturalistic study in veterans shows that completing an MBSR program can improve symptoms of anxiety and depression, in addition to reducing suicidal ideations, all of which are of critical importance to the overall health of the patients.