This study sought to find out teachers’ and principals’ knowledge and perception of school-based supervision practices in public secondary schools in Benin metropolis. To achieve this purpose, four research questions were raised. The descriptive survey research design was adopted for the study. The population of the study consisted of the teachers and principals in the Benin metropolis. A sample size of three hundred and sixty-three (363) principals and teachers was used. A structured questionnaire was used for the collection of data. The data were analyzed using descriptive statistics of mean and standard deviation for the research questions while the Chi-square and independent sample t-test were used to test the hypotheses. The findings of the study revealed that the teachers and principals were knowledgeable in the art of school-based supervision practices, and there were a lot of problems facing the effective practice of school-based supervision. The findings further revealed that years of experience was a determining factor in the art of carrying out school-based supervision. Therefore, appointing principals with at least ten years of experience and provision of modern facilities for school supervision were recommended.