Teacher appraisal is never an easy task, especially of teachers experiencing difficulties and failures. Nevertheless it is a requirement for good management, in our schools no less than our corporations. Forty elementary school principals in Israel described the informal methods they use to appraise teachers who are performing poorly. Most considered traits such as sensitivity to children and their needs as well as motivation, rather than professional standards or pupil achievement, as the main criteria in judging poor or outstanding teaching. Due to the sensitive nature of the issue, and the desire to avoid misjudgment and painful conflict, the principals took several precautions: they used several different formal and informal methods of appraisal; they relied on various information sources and sometimes they preferred to delay drawing final conclusions until a crisis or external complaint occurred. The discussion situates the current findings with other research on the obstacles to identifying, evaluating and providing feed back to poor-performing teachers.