Safety-net clinic patients are at risk for food insecurity, which is associated with poor diet quality and negative health outcomes. Research on the impact of interventions addressing food insecurity in health care settings is limited. The primary aim of this study was to determine the preliminary effectiveness of Community-Supported Agriculture (CSA) Partnerships for Health, a 23 week grant-subsidized CSA program, in improving dietary behaviors, self-efficacy to eat vegetables, food security, and overall health among safety-net clinic patients. This single-group pretest-posttest study used interviewer-administered surveys. Study participants were 48 safety-net clinic patients. Outcomes included fruit and vegetable intake, frequency of dark green and orange vegetable intake, self-efficacy to eat vegetables, eating habits, food security status and ability to afford to eat healthy meals, emotional health, social health, and general health status. Differences in values at postintervention versus preintervention were examined using two-sided paired t-tests, McNemar's tests, and generalized estimating equation models. The difference between postintervention versus preintervention values was statistically significant for a number of outcomes, including vegetable intake (p = .030), orange vegetable intake (p = .004), eating habits (p = .039), food security (p = .039), ability to afford to eat healthy meals (p = .003), and general health status (p = .039). Generalized estimating equation models showed similar associations. CSA Partnerships for Health may have the potential to improve dietary behaviors, reduce food insecurity, and improve overall health among safety-net clinic patients.