We evaluated the usefulness of premarin priming on exercise induced growth hormone release and the value of combining several growth hormone screening agents in a large population of prepubertal children. Two hundred five short healthy prepubertal children growing below the 5th percentile in height were studied. One hundred forty-four were screened with exercise following glucose ingestion, while 61 were primed with estrogen prior to glucose and exercise testing. Premarin priming did not significantly increase the number of our patients who responded to exercise nor to glucose; 86% and 88.5% of non-primed and primed patients, respectively, responded with a growth hormone increase greater than or equal to 8 ng/ml following exercise and glucose. Glucose loading alone was not associated with a high enough growth hormone rise to rule out growth hormone deficiency in most of our children. Age (less than or equal to 5 yr) was associated with lower post-exercise growth hormone levels and a higher failure rate to testing in both primed and non primed children. Premarin priming does not seem to alter the growth hormone releasing capacity to exercise of prepubertal children. The combined use of exercise, glucose loading and premarin priming in a single screening test does not improve on the results obtained by growth hormone exercise screening alone.