The purposes of the study were: to determine the relationship between class size and academic achievement among university students in first-semester calculus classes, and to compare opinions about the instructor, course, and classroom learning environment of university students in small first-semester calculus classes with those in large classes. The sample consisted of 225 university students distributed among two large and two small sections of first-semester calculus classes taught at the University of Texas at Arlington during the fall of 1987. Each of two tenured faculty members taught a large and small section of approximately 85 and 27 students, respectively. During the first week of the semester, scores from the Calculus Readiness Test (CR) were obtained from the sample and used as the covariate in each analysis of covariance of four periodic tests, a comprehensive final examination, and final grade average. The CR scores were also used in a logistic regression analysis of attrition rates between each pair of large and small sections of first-semester calculus. Three semantic differentials were used to test the hypotheses relating to student opinion of the instructor, course, and classroom learning environment. It was found that for both pairs of large and small first-semester calculus classes …