The effect of time limits on the completion rate of 8,290 students taking the reading comprehension section of the Academic Assessment and Placement Program (AAPP) was studied. The AAPP is a Tennessee configuration of items drawn from the College Board's multiple assessment programs and services item pool. It is a battery of tests used for diagnostic placement of Tennessee students into remedial or developmental courses. Students under 21 years old with an American College Tests (ACT) Composite Score of 15 or below and students 21 years old or older with no ACT test on file are required to take the AAPP tests in English, mathematics, reading comprehension, and logical relationships. For the study population as a whole, and by sex and age, no substantial effects of time limits were observed. Differential completion rates by race were noted at all 20 Tennessee State Board of Regents institutions evaluated, with whites having higher completion rates than blacks. Such differences should become a priority for study. Seven graphs are presented. (SLD)