The aim of this study was to determine the main characteristics of a "good teacher" through the use of questionnaires designed to assess teaching skills and competences, considering the point of view of teachers, principals, and students. In total, 82 teachers, 14 principals, and 625 middle-school students from 5 public schools in São Paulo state participated in this study. Two questionnaires were applied, one designed for teachers and principals and the other for students. First, teachers and principals completed their specific questionnaire, after which the other questionnaire was applied to the students. Both questionnaires contained multiple choice questions related to eight distinct subsections. The questions were answered through the use of a Likert scale, varying from 1 ("totally disagree") to 5 ("totally agree"). The comparisons of the frequency of responses among all questionnaire subsections between teachers and principals were analyzed using a Chi-Square and the z-test, with P-values adjusted to the Bonferroni method. The statistical significance level was set as P < 0.05. The subsection "class atmosphere" presented the highest percentage of response "totally agree", closely followed by "professional engagement". Significant differences (P < 0.05) in responses were observed between teachers and principals for "teaching planning and practice", "use of time and material resources to develop classes", and "professional engagement" domains. In summary, it was demonstrated that some teaching characteristics might be more important than others, with some of these characteristics exhibiting significant differences between groups. Nevertheless, it is crucial to emphasize that all assessed educational domains may be recognized as critical teaching qualities, as all of them presented high levels of "totally agree" responses.