The effects of implanting pellets of stilbestrol and testosterone subcutaneously were studied with 42 growing-fattening pigs. Two lots of seven pigs each were assigned to each experimental group—control, testosterone implanted, and stilbestrol implanted. The implantations were made at the beginning of the experiment and 12 weeks later. The pigs averaged 43 pounds at the start of the experiment and were slaughtered as they reached 210 pounds. The following characteristics were studied: average daily gain, feed per 100 pounds gain, daily feed consumption, dressing percentage, length of carcass, weight of regular ham, percent of external fat in the regular ham, eye muscle measurement, fat back thickness, length of femur, specific gravity of the femur, weight of leaf fat, and seediness of the fresh belly. Of these characteristics, seediness of the belly in the stilbestrol group is the only one that showed a significant deviation from the control. The reproductive organs of the treated pigs showed definite evidence of hormonal stimulation.