A Coordinated Research Programme (CRP) on assessment of environmental exposure to mercury in selected human populations as studied by nuclear and other techniques was initiated by the IAEA in 1990 in collaboration with WHO. The purpose of this CRP is to promote national and regional studies to evaluate the exposure of selected population groups to mercury and methylmercury and to estimate potential health risks in these groups. The programme is focused on the analysis of human head hair for the determination of mercury and methylmercury. This CRP has two main components: (i) identifying population groups that are at risk, and (ii) studying health effects in the exposed persons, particularly pregnant women and the babies born to them. This report contains the discussions held during the second Research Co-ordination Meeting (RCM) for the CRP which took place in Kuala Lumpur, Malaysia, under the sponsorship of the University Kebangsaan Malaysia and papers presented at this meeting. Refs, figs and tabs.