The study investigated the factors contributing to teacher effectiveness in senior high schools in the Kassena Nankana West District. A descriptive survey design with a sample of 100 teachers was used for the study. A self-designed questionnaire was used for the data collection. Means and standard deviations and independent samples t-test were the statistical tools used in the study. The objectives of the study were to find how headmaster supervision contributes to teacher effectiveness; find students’ attitude that contribute to teacher effectiveness; how community participation contribute to teacher effectiveness. Means and standard deviations and the independent samples t-test were the statistical tools used in the study. The findings of the study were showed that; headmasters involved teachers in decision making in schools, students’ participation in classroom work was appreciable, and communities gave teachers some fringe benefits. It was recommended that headmaster supervision should be strengthened since involving teachers in decision making in school brings about teacher effectiveness. Again teachers should relate and encourage students to participate in classroom work since that contribute to teacher effectiveness. It was concluded that headmaster supervision is very important since that contribute to teacher effectiveness in school.