In order to determine the value of a positive exercise test (ET) (i.e. ischaemic ST depression) without chest pain observed after a myocardial infarction (MI), 102 ET's were reviewed. ET was performed without anti-ischaemic drugs. The mean time-lag between MI and ET was 51 +/- 55 months. The MI was inferior in 26 cases, inferior and/or posterior in 74 cases and of undetermined location in 2 cases. Thirty patients had both ST depression and chest pain (group 1); 35 had electrocardiographic signs of ischaemia without pain (group 2), and 37 had neither chest pain nor signs of ischaemia (group 3). Age, sex ratio, site of infarction and time-lag between MI and ET were similar in all three groups. The post-ET follow-up period was 33 +/- 18 months (range: 6 to 66 months); 2 patients in group 3 were lost sight of. There was no significant difference between groups 1 and 2 as regards total duration of ET, workload attained, heart rate, systolic arterial pressure, pressure-rate product and amplitude of ST depression at maximum exercise level. Group 3 differed from the other 2 groups in workload attained (p less than 0.05) and in pressure-rate product (p less than 0.05 vs group 1, p less than 0.01 vs group 2). There was no significant difference between groups 1 and 2 as regards post-ET events (recurrent angina, reinfarction, coronary bypass, transluminal angioplasty).(ABSTRACT TRUNCATED AT 250 WORDS)