We studied the frequency of ST-T changes and ischemic heart disease (IHD) in prednisolone (PSL)-treated systemic lupus erythematosus (SLE) patients and compared them with the age-matched control of rheumatoid arthritis patients not receiving PSL. Twenty-five (38%) of the 65 SLE patients revealed ST-T changes as ST elevation (4%), ST depression (36%) and T wave flattening or inversion (60%). Among the control patients 4 (10%) had T wave flattening or inversion. The frequencies of ST-T changes in patients receiving total PSL dose of upto 5g and greater than 5g were 23% and 48%, respectively. Four patients developed IHD at an unusually young age during remission of SLE while receiving low dose of PSL and 2 of them later died of myocardial infarction (MI). The latter 2 patients had received PSL pulse therapy prior to MI. Regular ECG check up for SLE patients while they are on low dose PSL or pulse therapy may help reveal early ECG abnormalities and thus detect and treat one of the major risks of long-term effects of corticosteroid therapy.