Objectives: To investigate a possible relationship between hypertriglyceridemia and the coagulation system, a Cardiovascular Risk Factor Two-township Study was conducted in Taiwan. Design: A case-control study. This longitudinal, prospective study focused on the evolution of cardiovascular disease risk factors with emphasis on haemostatic factors. Subjects: Hypertriglyceridemic subjects (triglyceride <2.26 mmoll+1, n = 327) and age-matched normal controls from a population screening program. Main outcome measures: Haemostatic parameters measured in this study included prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, factors VIIc and VIIIc, and antithrombin-III and plasminogen levels. Results: In our male hypertriglyceridemic subjects, aPTT was not significantly reduced, while significant elevations of factor VIIIc, factor VIIc, and plasminogen and antithrombin-III levels were noted. In the female hypertriglyceridemic subjects, the elevation of factor VIIc, factor VIIIc, and plasminogen and antithrombin-III levels was highly-significant, whereas aPTT was not significantly reduced. Unexpectedly, the levels of the established coronary risk factor, fibrinogen, did not show a statistically different change. Similar to previous data, our hypertriglyceridemic subjects also presented with hyperinsulinemia, glucose intolerance, upper body obesity, and elevated blood pressure. Conclusions: Despite the fact that in population studies, triglycerides do not consistently appear to be an independent risk factor for coronary heart disease, our data suggest that a pronounced increase in triglycerides warrants aggressive therapy, because this increase may be associated with a hypercoagulable state. This phenomenon contributes another perspective to the study of higher cardiovascular mortality in hypertriglyceridemic subjects.