Sixteen collegiate women lacrosse players consumed either creatine (C, n= 7) or a placebo (P, n= 9) for 5 weeks during their preseason conditioning program (20 g [middle dot] d-1 for 1 week and 2 g [middle dot] d-1 for 4 weeks). Pre-and posttesting consisted of body composition, muscle endurance test, blood lactate response to the endurance test, 1 repetition maximum (1RM) bench press and leg extension, and blood glutamyltransferase (GGL) and blood urea nitrogen (BUN). Testing revealed that 1RM bench press significantly increased in both groups, with the C group improving significantly more than the P group (6.2+/-2.0 and 2.8+/-1.8 kg). Percent body fat by skin-fold decreased significantly more in C than the P group (-1.2+/-0.9 and 0.3+/-0.8), but was not different by group by hydrodensitometry. No significant differences between groups were found for all other measures, but significant time effects were noted for body weight gain (0.5+/-3.2 kg), 1RM leg extension (1.4+/-4.1 kg), BUN (0.07+/-0.03 mmol [middle dot] L-1), total work during the muscle endurance test (283.5+/-387.3 watts), and fat-free mass by skinfold (0.7+/-1.2 kg). In summary, a regime of dietary creatine supplementation significantly improved upper-body strength gain and decreased the percent body fat as assessed by skinfold in women athletes engaged in a resistance-training program.