Serum PGF2α titers were examined in 8 sober alcoholic males who had attempted suicide and 19 nonattempting alcoholic males. Two of the 8 attempters had used violent means and the remaining 6 had used nonviolent means. The suicide attempters had significantly lower PGF2α titers, relative to the nonattempters (p < 0.005), with the violent attempters expressing maximally reduced titers. There were no significant differences between the groups with respect to age, alcohol consumption patterns, or admission scores on the Beck Depression Inventor