Effects of exercise, social facilitation, and delayed conditioning after vi exercise on the learning behavior of 5 to 6-inch rainbow trout, Salmo gairdneri, was measured in a conditioned avoidance response apparatus. The conditioning schedule contained an intertrial interval between alternate presentations of conditioned (light) and unconditioned (shock) stimuli. This randomization eliminated learning losses found in a previous study. Mean percentage avoidance, the measurement of learning, did not decrease significantly during conditioning trials. Exercised fish learned avoidance better than did non-exercised fish. Mean percentage avoidance for fish exercised at 0.5 ft/sec was 66.3; at 1.0 ft/ sec, 1.5 ft/sec, and no-exercise, mean percentage avoidance was 68.2, 68.9 and 65.0, respectively. Social facilitation affected learning in the one, two, and three fish per cell tests, where mean percentage avoidance was 55.5, 68.9, and 81.0 percent, respectively. A delay of 24 hours between exercise and conditioning resulted in decreased learning levels. Mean percentage avoidance was 60.3, 63.5, 67.7, and 53.7 for the 1-, 2-, 2-, and 24-hour delay tests, respectively; however, mean percentage avoidance for the last 60 trials of each test indicated the 1-, 2-, and 4-hour delay tests were all similar, over 70 percent, while mean percentage avoidance for the 24-hour delay test was only 57.8 percent.