Abstract: To investigate the effect of mental stress on serum triglyceride concentration. This was a case control study. Subjects were 100 patients with hypertriglyceridemia and 100 healthy without hyperlipidemia. A self-administered questionnaire assayed the exposure to stress and anxiety in the past 6-12 months with the six point likert scale. Data were analyzed by SPSS software using chi-square, independent sample t-test and Pearson�s tests. For all analyses, alpha level was 0.05. Mean of stressful life events in case group was 16.87±10.39 and in control group was 4.15±2.25. There was a significant difference between two groups (p<0.001). The results indicate that the stressors in the past 6-12 months may elevate the level of triglyceride. Therefore hypertriglyceridemia is one possible mechanism of ischemic heart disease in stressed people.