It is important for the coach, athlete, and researcher to be aware of the physiological and performance changes that occur during a college basketball career. The purpose of this investigation was twofold: (a) report measures of body composition, aerobic fitness, flexibility, power, vertical jumping ability, and strength in freshman basketball players; and (b) report changes in these fitness variables between freshman/sophomore, sophomore/junior, and junior/senior years. Preseason measures for body weight, percent fat, maximum oxygen uptake (VO2 max), one-repetition maximum (1-RM) bench press and squat, sit-and-reach flexibility, vertical jump, and peak and average power during vertical jump are reported. The basketball players were lean (8.3% fat) and maintained low percent fat despite a mean 7.4-kg increase in body weight between freshman and senior years. Compared to professional and college basketball players, the freshmen had relatively high VO2 max (over 50 ml- kg-1 min−1) and maintained this value across their college careers. No significant change was observed in sit-and-reach flexibility, but vertical jump increased 4.9 cm between the freshman and senior years. Vertical jump peak power output increased 570 W while average power output increased 274 W. Finally, bench press and squat 1-RM values both increased a substantial 22 and 44.7 kg, respectively. This information should be of value to coaches for both developing realistic training objectives and for evaluating progress of athletes. © 1993 National Strength and Conditioning Association.