This study investigated the influence of internal supervision of instruction on improving Teacher performance in secondary schools in Edo State. Four research questions and four hypotheses were postulated to guide the study. Descriptive survey design was used. From the population of 1110 teachers, of Edo State, 444 teachers were sampled using proportionate stratified random sampling technique. The sampled teachers represent 40% of the entire population. A thirty-two (32) item questionnaire was sent to experts for validation and they offered useful suggestions after their review. Data were analyzed using mean, standard deviation, t-test and analysis of variance (ANOVA). Mean and Standard Deviation were used to answer all the research questions posed in the study.  Four null hypotheses formulated were tested using t-test and ANOVA at 0.05 level of significance. The study found that internal supervision of instruction had positive influence on improving teacher performance in Edo State. The study found that classroom visitation, observation technique, demonstration technique and evaluation technique had a positive influence on teacher performance in secondary schools in Edo State. The study also found that there was no significant difference on the influence of internal supervision in improving teacher performance in secondary school based on gender, location, educational qualifications and teaching experience. Based on the findings, it was recommended that:  supervisors and Principals should endeavour to ensure that classes are regularly visited to enable secondary school teachers to improve more in their performances.

Keywords: Edo state, Instruction, Secondary Schools, Teacher Performance, internal supervision