Aims. We evaluated the interaction effect between depressive symptoms and dietary habits on 30-day development of cardiovascular disease (CVD) (death or rehospitalization) in elderly, acute coronary syndrome (ACS) survivors. Methods. During 2006–2008, we recorded 277 nonfatal, consecutive ACS admissions (75 ± 6 years, 70% males, 70% had diagnosis of myocardial infarction) with complete 30-day follow-up. Assessment of recent depressive symptoms was based on the CES-D scale. Among sociodemographic, bioclinical, lifestyle characteristics, the MedDietScore that assesses the inherent characteristics of the Mediterranean diet was applied. Results. 22% of the ACS pts developed a CVD event during the first 30 days (14.8% rehospitalization and 9.4% death). Patients in the upper tertile of the CES-D scale (i.e., >18) had higher incidence of CVD events as compared with those in the lowest tertile (21% versus 8%, P = .01). Multiple logistic regression analysis revealed that 1-unit increase in CES-D was associated with 4% higher odds (95% CI 1.008–1.076, P = .01) of CVD events; however, when MedDietScore was entered in the model, CES-D lost its significance (P = .20). Conclusion. Short-term depressive symptoms are related to a worsen 30-day prognosis of ACS patients; however, this relationship was mediated by Mediterranean diet adherence.