The main purpose of this study was to investigate the Implementation of School Improvement of Program in Adama Government Secondary Schools with particular emphasis on Perception, Practices and Challenges that affect its proper implementation and find solution to ensure the success of SIP in Government Secondary Schools of Adama City Administration. In order to achieve this purpose, mixed research design that uses both quantitative and qualitative data was employed. The study was conducted in four secondary schools found in Adama City Administration. The major sources of data were teachers, principals, School Board, PTA members, Student Councils, and Officials from Adama City Education Office. The selection of sample teacher respondents was carried out using simple random sampling technique; whereas school boards, principals, vice principals, Educational Officers, SIC and members of PTA were selected by using purposive sampling technique. The data were collected through questionnaire, interview, and FGD. After the data were collected, they were processed through SPSS-V20 software; and analyzed using descriptive statistic like frequency, percentage, mean, standard deviations and ranges. Additionally, t-test was also used to measure the relationship of teachers and other respondentsâ€™ responses to some variables of the study. The results of the study showed that, the extent of teachers, Leaders and parents participation in planning and implementing SIP was low; the mechanism through which monitoring and evaluation were practiced to support SIP implementation was not in position to effectively run SIP. In addition, most of the activities across the four domains were implemented at moderate level. Hence, from the result of the study the overall implementation of SIP was moderate. Lack of having properly prepared plan for SIP implementations, lack of proper understanding of SIP at school level, weak monitoring and evaluation system of SIP, lack of leadership capacity, different organs of the school not properly understanding their role in SIP, lack of sufficient stakeholders involvement in SIP and giving less attention for SIP were major factors that negatively affect SIP implementation. To alleviate the challenges and to improve the implementation of SIP it was suggested that, the schools should have properly prepared planning, preparing adequate awareness creation program to ensure practical involvement of active participation of all stakeholders on SIP implementation, making school committee functional and strengthening monitoring and evaluation on school improvement program implementation.