This article reports on a study of 82 male suicides in New Zealand prisons (1971-88) & police cells (1980-91) to examine evidence of suicide clusters. There were 38 suicides in prisons & 44 in police cells. The different characteristics of prison & police cell clusters of suicide indicated separate transmission of the contagious component of suicide between these groups. Distinct strategies to reduce clusters are required in each setting. (16 Refs.)