Twenty-four hour urines were obtained from groups of male and female volunteers recruited from urban populations in developed and developing countries (UK, USA, Japan and Nigeria) an from agriculture-based Polynesian population (Tokelau Islands). The urines were collected on typical working days, with minimal disturbance to subjects' normal routines. High-performance liquid chromatography was used to determine catecholamine concentrations in each urine, providing a basis for calculation of total 24-hour excretion. Mean 24-hour excretion of noradrenaline and adrenaline was low in the Polynesians compared to the modern, urban groups, and low in women compared to men. Discussion of the results includes assessment of the possible influences of artefact, physical characteristics of the population samples, physical environment and social and psychological factors.