BACKGROUND: There are epidemiological clinical studies that describe the relationship of decreased serum cholesterol levels or their treatment with suicides, offensive actions and depression. METHODS: We studied 140 patients who were hospitalized at Asan Foundation Jeongup Hospital (in Korea) via emergency room after suicide attempts and whose serum cholesterol levels were acquired during 53 months (from Jan. 1. 1995 to May 31. 1999). They were evaluated with the use of t-test. The serum cholesterol levels were compared between the control group of 140 persons who underwent health check ups and 140 patients who were of similar age and sex ratios. RESULTS: Subjects showed significant decrease in serum cholesterol levels in comparison with the control group. Low serum cholesterol levels were related with the severity of suicidal attempts. 1) The subjects showed lower serum cholesterol levels than the control group(150.51+/-56.69mg/dl vs 185.61+/-31.94mg/dl; t= 6.382, df=278, P<0.001) (Table 3). 2) Those who killed themselves showed statistically significant decrease in serum cholesterol levels than those who survived after their suicidal attempts(169.13+/-49.29mg/dl vs 135.89+/-34.14; t=2.005, P<0.05) (Table 4). CONCLUSION: This study was carried out in farming and fishing villages of Korea. The result showed that the decrease in serum cholesterol levels increased the risk of suicide trials. This fact is similar to the results of the previous studies performed at other farming and fishing communities. In addition, those who killed themselves had lower serum cholesterol levels compared to those who survived suicide attempts. This relationship was associated with depression.