Supervision of education in Kenya has adopted the inspection model which is traced back to the colonial era. The objective of the study was to investigate perceptions of primary school teachers on the effectiveness of supervision in their professional development. The needs assessment theory was adopted for this study. This study was conducted in Teso North district. The study adopted descriptive survey research design. A total of 180 respondents participated. Thirty (30) head teachers from the selected schools were selected, while the 150 teachers were selected by simple random sampling. Data were collected by use of a self-administered questionnaire for teachers and a structured interview schedule for head teachers. Data were analyzed and presented by use of frequency tables and t-test statistics. It was established that teachers generally agree that supervision enhances their professional development. It is envisaged that this study will be useful in improving both instructional and supervisory practices as teachers will get to be more aware of what is expected of them of the supervisory practices. The study recommends that the government needs to recruit and deploy more QASOs at Zonal levels in each district to increase the frequency of supervision.