As prevalence of metabolic syndrome has rapidly increased over the past decade, lifestyle changes including dietary habits are considered as a therapeutic cornerstone for metabolic syndrome, cardiovascular complications and type 2 diabetes. We evaluated the effectiveness of a telephone-delivered nutrition education to improve metabolic parameters compared with a single-visit with a dietitian in subjects with metabolic syndrome. A total of seventy-one adults who met diagnostic criteria for the metabolic syndrome were randomly assigned to either the single-visit group or the in-depth nutrition education group during a 3-month intervention study period. The in-depth telephone-delivered nutrition education group had an initial visit with a dietitian and additional two telephone counseling during the first 4 weeks of the study periods. Sixty-six subjects completed a 3-month intervention study. The trial examined participant's anthropometric changes and dietary intakes as well as changes in the metabolic syndrome factors. At the end of the trial, the in-depth nutrition education group showed significantly higher reduction in weight, body fat and abdominal circumference compared with the other group (p < 0.05). In the in-depth nutrition groups, the prevalence of metabolic syndrome was decreased to 45.5%, while 69.7% of the subjects were metabolic syndrome patients in the single-visit group (p < 0.05). These results demonstrate that the telephone-intervention counseling is a feasible mean to deliver dietary intervention in patients with metabolic syndrome.