Background: The incidence of the Achilles tendon ruptures (ATR) seems to be increasing due to changes in life style and intensified sports activities in recent years. Intrinsic and extrinsic factors have been implicated as predisposing risk factors to rupture. The purpose of this study was to investigate whether the high serum lipid concentrations could be an intrinsic factor in patient with complete ruptures of Achilles tendon. Methods: The data were collected from the records of 47 patients with complete rupture of Achilles and the control group consisted of 26 subjects. Results: Total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) concentrations of the patients with ATR were higher (p < 0.001), and their high-density lipoprotein cholesterol (HDL-C) was lower than the control group (p < 0.05). Moreover, the concentrations of triglyceride (TG) and very low-density lipoprotein cholesterol (VLDL-C) were significantly higher than controls (p < 0.05). Conclusions: The causes of ATR are multifactorial and still unclear. However, high serum lipid concentrations might be considered, as a predisposing factor in patients with complete rupture of Achilles tendon and further investigations with larger groups would be better. (C) 2003 Published by Elsevier Science B.V.