The possibility of using the grade differential statistic in college admissions decisions is explored. The grade differential statistic is the mean difference between the freshman college grade point average (GPA) and the high school GPA (HSGPA) for freshman college entrants from a particular high school. Rather than being an index of high school academic quality, the index appears to be a measure of the grading practices of high schools. In some instances, it may be useful to consider this index in admissions decisions. Only high schools that admitted at least 16 students per year to the University of California at Berkeley in the fall of 1989 were included in this study. Data for 313 students for fall 1987, 346 students for fall 1988, and 335 students for fall 1989 were used. Results show that the grade differential statistic is consistent from year to year. Multiple regression equations show that the statistic, when used in conjunction with HSGPA, adds considerably to the coefficient of determination and the predictive power of the HSGPA. However, at the University of California at Berkeley, even if the grade differential statistic was reliable and valid for schools contributing 5 students, it could be used in only about 50 percent of the decisions. Nevertheless, there are situations in which it could be useful. Five tables present findings from the analysis. (SLD)