This book identifies teachers' perceptions of the teacher-student relationship based on indicators of conflict and affinity, relating them to the variables of academic performance, age and gender of the students and teachers. A cross-sectional correlational study was carried out with 10 secondary school teachers from a state public school, who assessed 10 students using the Teacher-Student Relationship Scale (ERPA). The results suggest that female teachers tend to have greater affinity with female students and conflictual relationships with male students. When correlating the academic performance variable with the affinity and conflict indicators, there was a weak positive correlation between the conflict indicator and academic performance in Philosophy. However, in Geography, there is also a weak positive correlation, but with the affinity indicator.