Emotion is an important factor that affects people's lives in many areas including their productivity at work. For this reason, teacher emotions, defined as emotional states related to the learning activities in educational settings, are very important in the classroom environment. In this study, the relationships of science teachers' emotions with demographic and school variables were examined. 185 science teachers at public and private middle schools in Mugla Province participated in the research in the fall semester of 2019-2020. In the study, data were collected using the Personal Information Form and the Teachers' Instructional Emotions Scale. In descriptive analyzes, mean and standard deviation were used whereas non-parametric Mann Whitney U and Kruskal Wallis H tests were used to determine the relational findings since the data did not show normal distribution. It was found that science teachers' positive emotions of pride, pleasure, and hope had a higher mean value than negative emotions of anger, anxiety, and frustration. Relational analysis revealed that there was significant difference between science teachers' instructional emotions in terms of gender, age, professional experience, school location and the socio-economic status of the school. There was no significant difference in the weekly course hours, weekend course hours and class size variables.