Using records from the Regional Poisoning Treatment Centre in Edinburgh, a 6 point scale was devised measuring sociopathy, alcohol problems, previous in-patient and outpatient treatment, and previous parasuicidal acts. The percentage of repeaters in a given catagory ranged from 5% for those who scored 0, to 48% of those who scored 5 or 6. Since the scale enables patients to be classified according to their level of risk, it is a reasonably useful and valid instrument.