Stressful health situations may compromise spouses’/partners’ ability to provide patients with support. We tested whether partner status/partner presence in the emergency department (ED) were associated with patients’ adherence to daily cardiovascular medications and whether effects differed by age/gender. Participants were 189 patients evaluated for acute coronary syndrome at an urban academic ED (MAge = 62.18; 57.1% male; 58.7% Hispanic). Participants self-reported partner status/partner presence. Medication adherence was measured using an electronic pillcap. For male patients, having a partner was associated with increased adherence in the first month post-discharge, OR 1.94, p < .001, but having a partner present in the ED was associated with lower adherence, OR 0.33, p < .001. The opposite effect was evident for female patients. Partner status/partner presence in the ED are associated with medication adherence during the first month post discharge, with opposing effects for male and female patients.