The main objective of this study was to assess the Practice and Challenges of schoolbased CPDrnin secondary schools of Jimma Zone. To achieve this purpose the descriptive survey design wasrnemployed. The sampling technique employed was simple random sampling, availability andrnpurposive sampling. Data were collected from149 teachers, 16 school principal’s 18 vicernprincipals, 16 CPDleaders,40 department heads7 supervisors 14 woreda education officernteachers’ development unit expert personnel and 5 zone education office teachers’ developmentrnunit expert personnel with the total of 265 participants out of693 study populations. The datarngathering tools were questionnaires, interview and focus group discussion. Data were analyzedrnby using percentage, mean and standard deviation besides using both qualitative andrnquantitative method. Consequently, the obtained result confirmed that the level of teachersrnunderstanding on contents, significance and objective on school based CPD is in adequate, thernschool principals and teachers were less successful in implementing effective SBCPD, thernteachers considers school based CPD as extra workload without professional agenda, thernabsence of career progression based on the practice of SBCPD, the lack of sufficient time andrninsufficient budget allocation to implement SBCPD were consider as a major challenges and thernteachers were less benefited from SBCPD in updating their knowledge of subject matter. It wasrnalso identified that supervisors and woreda education office teachers development unit expertrnpersonnel were un satisfactory in enhancing the implementation of SBCPD, more over the workrnof the teachers were hindered with complicated work conditions and the lack of necessaryrntraining on school based CPD activities were among the problems entangled the implementationrnof SBCPD. In order to solve the problems and alleviate the challenges a collaborative work isrnrecommended to the concerning bodies from the school level to regional education bureau andrnother stakeholders to capacitate the teachers, principals and supervisors through providingrntraining, allocating budget and improving their working conditions.