In a group of 20 college subjects, the fasting serum chromium level was found to correlate with the fasting serum insulin level (r = 0.512, p less than 0.05), with the percentage of ideal body weight (r = 0.637, p less than 0.01), and with the triceps skinfold thickness (r = 0.525, p less than 0.02). The relative chromium response at insulin peak was inversely correlated with the total insulin (r = -0.451, p less than 0.05) as well as with the ratio of the total insulin to the total glucose (r = -0.554, p less than 0.02). In order to examine the close relationship between chromium and insulin, the 20 subjects were divided into age- and sex-matched lower insulin secretors and higher insulin secretors based on individuals' total insulin levels calculated as the sum of six measurements in microunits/ml during a 3-h oral glucose tolerance test. The 10 subjects in LI had total insulin levels less than 500, and the 10 subjects in HI had total insulin levels equal to or greater than 500. The means (+/- SEM) of total insulin for LI and HI were 354 +/- 39 and 740 +/- 46, respectively (p less than 0.001). The relative chromium response was significantly higher in LI than that in HI (198.0 +/- 31.0% and 76.2 +/- 18.0%, respectively; p less than 0.005); and the ratio of the total insulin to the total glucose was significantly lower in LI than that in HI (0.585 +/- 0.067 and 1.286 +/- 0.094, respectively; p less than 0.001).