The reinforcing effects of positive characteristics in maintaining teachers' and students' psychological health have been well documented. However, there has been very little research into the determinants of what constitutes positive characteristics among teachers. Neither the full role played by mindfulness nor the psychological capital of teachers with positive characteristics remains unknown. This study marks the beginning of an investigation into such an issue. The sample of the study involved the participation of 374 teachers. In Model 1, the mediating role of psychological capital was tested in the relationship between mindfulness in teaching and teacher positivity. Meanwhile, in Model 2, the mediating role of mindfulness in teaching was tested in the relationship between psychological capital and positive teacher characteristics. In Model 1, the standardised path coefficients between the variables were not found to be statistically significant, thus prompting the test of a second structural model. The results showed that mindfulness in teaching appeared to constitute a full mediator in the relationship between psychological capital and positive characteristics among primary school teachers.