Objectives: Although surf programs for individuals with psychological and physical conditions exist, data evaluating such programs are limited. This study examined psychological outcomes among 74 active duty service members participating in the Naval Medical Center San Diego surf therapy program. Design: The study used a single-group, longitudinal design involving repeated measurement to assess outcomes following the program and within sessions. Method: Service members completed self-report questionnaires before and after the 6-week program and before and after each surf therapy session. Results: Total scores for symptoms of depression (beta = -2.31, p < .01), anxiety (beta = -3.55, p < .001), PTSD (probable PTSD subgroup only; beta = 14.55, p < .001), and negative affect (beta = -6.40, p < .001) significantly decreased from pre-to post-program, while positive affect significantly increased (beta = 9.46, p < .001). During each session, depression/anxiety symptoms significantly lessened (beta = -3.35, p < .001) and positive affect significantly improved (beta = 8.97, p < .001). The magnitude of within-session changes did not differ across sessions (p > .05). Results for subgroups with probable PTSD or major depressive disorder were comparable to those of the full sample. Conclusions: Immediate benefits of surf therapy included significantly reduced depression/anxiety and increased positive affect. As a complementary intervention, surf therapy may improve depression, anxiety, and PTSD symptoms with potentially unique benefits on affect.