We evaluated the relationship between nesfatin-1 and acute myocardial infarction (AMI) and Mediterranean diet scores. 67 patients with AMI and 33 patients with normal coronary arteries (control group) were included in the study. The patients with AMI were divided into 2 groups based on low (< 32) (n = 33) and high values of the synergy between percutaneous coronary intervention with Taxus and cardiac surgery (SYNTAX) scores (>= 34) (n = 35). Mediterranean diet score, serum nesfatin-1 concentrations and all other data were compared between the groups. Serum nesfatin-1 concentrations were significantly lower in 67 AMI patients (both the high and low SYNTAX groups) than in the control group (p < 0.001). Moreover, serum nesfatin-1 concentrations were lower in the high SYNTAX group than those in the low SYNTAX group (p < 0.001). There were positive correlations between the serum nesfatin-1 concentrations and Mediterranean diet scores in both the AMI patients and the control subjects, and there was a negative correlation between the serum nesfatin-1 concentrations and SYNTAX scores in the AMI patients. This study has shown that serum nesfatin-1 concentrations are closely related to the severity of AMI and Mediterranean diet scores.