This study examined what moral issues meant to practicing teachers. Finnish secondary teachers described moral dilemmas they had experienced during their teaching careers and principles they used to solve them (particularly situations in which they had difficulty deciding how to act). The narrative of one female teacher concerned about smoking at her school is highlighted. Though smoking was forbidden by law in Finnish schools, both teachers and students broke this rule in several ways. This study adopted three interpretive viewpoints from the field of philosophy and ethics to examine the case, emphasizing the ethics of purpose, rules and principles, and probability. The analysis uncovered the teacher's background beliefs, which guided her ethical reflection on smoking at school. These included her own values which guided her educational practice. Her attitudes and concerns were identified as factors influencing her practical reflection. Her perceptions of the professional code of ethics were revealed in her reflection on the rules and principles guiding her educational practice in the case of smoking. While legal norms and organizational morality guided the standards teachers applied to smoking, teachers' own interpretations of rules and principles were the most important sources of standards guiding their professional practice. (Contains 34 references.) (SM)