Head teachers in Kenya are subjected to periodic evaluations. An effective head teacher evaluation results in improvement of performance of both head teachers and the institutions they lead (development), determine the extent to which head teacher performance meets pre-set performance standards (accreditation) and hold head teachers accountable for their actions (accountability). The study set to investigate qualitatively, the developmental aspect (or professional growth). This was done through focus group interviews and self administered questionnaires. Relevant documents on head teacher evaluation were also analyzed. Findings revealed that head teacher evaluation met accreditation and accountability aspects of evaluation. The developmental aspect was ignored. The study therefore calls for a shift from the practiced summative to formative evaluation if evaluation is to positively influence head teachers' professional growth.