By means of a critical incident technique using 66 suicide studies a 55 item true/false inventory was developed. This inventory was administered to 213 male psychiatric patients, who were divided into 4 groups according to history: threatened, attempted, threat & attempted, no suicide. A Chi square analysis differentiated (.001 level) the combined as well as the 3 subdivided suicide groups from the no-suicide group. The suicide groups could not be differentiated from each other.