The effect of indomethacin on ordered growth in length and width of the femur was studied in 48 adolescent rats given 2 mg/kg/day of the drug, a regimen previously shown to inhibit fracture healing. The animals were given either indomethacin suspension, or the vehicle alone, orally for 6 weeks. All the animals tolerated the treatment well. During drug treatment the femur distal to the intertrochanteric crest grew about 7 mm in length. Indomethacin plasma levels were about 1 microgram/ml in the indomethacin-treated animals. Indomethacin did not inhibit ordered growth in either length or width. This indicates that indomethacin does not inhibit the normal homeostasis of the skeletal system in adolescent rats.