Explored the relationship between parasuicide & the lunar cycle in 20,919 parasuicide patients (aged 16+ yrs) during 222 complete lunar cycles from January 1, 1969 yielding 6556 consecutive days. Analysis showed a pattern characterized by an increase in parasuicide in the 1st & 3rd wks of the synodic month, corresponding to the new moon & the full moon. The effect accounted for 0.7 out of the average of 46 parasuicides per 100,000 adults per lunar year, a rate that fails to reach significance.