The purpose of this qualitative research was to describe the opinions of teachers' students toward teachers who smoked in Thailand. The population was teachers' students (N=30) in their 1st--5th academic year of the Faculty of Education who participated based on purposive sampling according to eligibility criteria. The QDA Miner Lite program was used to analyze the qualitative data. The results indicated that the teachers' students understanding of a teacher was a person who conveys knowledge, experience and life skills in various fields for students both inside and outside the classroom and school. They should be a good person with knowledge and qualifications, displaying exemplary maturity in every way and be a role model. Like a family that gives love and keeps training and teaching in the right way. A teacher should be a good adviser and listen to problems. The ideal teacher must love to teach proficiently and be knowledgeable in what is being taught, allowing students to understand various forms of knowledge and be current. Smoking also affects being a teachers' students, in terms of inappropriateness and was not suitable for future teachers as it could affect the image of the organization. It also has harmful effect on health. A method that is likely to help prevent smoking among teachers' students and teachers is to create awareness through training and organizing various projects such as establishing a smoking cessation treatment center and campaigning for ways to replace smoking or to refrain from smoking.