Effects of supervisory monitoring on performance quantity and quality were examined. Experiment 1 participants performed 2 tasks and were monitored periodically on 1 or both tasks, with outputs either identifiable or unidentifiable. Experiment 2 compared several monitoring procedures varying in quantity emphasis. In Experiment 1, an apparent quantity focus positively affected quantity but created quantity and quality decrements on the unmonitored task. Experiment 2 indicated that these effects were most pronounced when monitoring explicitly emphasized quantity. Despite the positive effect on the monitored task, monitoring had a negative influence on a composite quantity-quality performance measure, with this interpreted in terms of changes in participants' speed-accuracy criteria. Some important implications for supervisory practices in organizational settings are discussed.