This study was designed to measure ischaemic pain during and after infusion of adenosine. In a double-blind, placebo-controlled, crossover study, eight ASA 1 male volunteers received infusion of adenosine 100 micrograms kg-1 min-1 or placebo for 10 min. This was repeated 1 week later with the alternate infusion. Pain measurements were made during tourniquet-induced ischaemia in an exercising arm before infusion, during infusion and for 24 h afterwards. Pain was reduced significantly in the adenosine group compared with the saline group during infusion (median difference 20.8; 95% confidence interval 2.0-40). There was no significant difference in pain after infusion and there were no significant changes in cardiovascular variables. During infusion of adenosine, transient mild chest discomfort, shortness of breath and facial flushing occurred. We conclude that adenosine had measurable effects on ischaemic pain which were not sustained after discontinuation of infusion.