An association between low levels of serum cholesterol and violent or suicidal behaviour has frequently been reported. However the role of serum cholesterol in the cycle of violence (Widom, 1989) has not been studied. The aim of this study was to investigate association between exposure to violence during childhood and used adult violence in suicide attempters with low and high serum cholesterol levels. 81 suicide attempters were assessed with the Karolinska Interpersonal Violence Scale (KIVS) measuring exposure to violence and expressed violent behaviour in childhood (between 6 and 14 years of age) and during adult life (15 years or older). We used median split to dichotomise groups below and above median serum cholesterol. In patients with serum cholesterol below median, the correlation between exposure to violence as a child and used adult violence was significant (rho=0.52, p=0.002), while in patients with serum cholesterol above median, the correlation between exposure to violence as a child and expressed violent behaviour as an adult was not significant (rho=0.25, p=0.2). Comorbid substance abuse predicted violent behaviour as an adult only in patients with serum cholesterol above median. Serum cholesterol may modify the effect of the "Cycle of Violence".