This study on the Assessment of the implementation of Islamic Studies Curriculum in Senior Secondary Schools in North-West Geo-political Zone, Nigeria. was inspired as a result of stake holders in Islamic studies education concern over poor performance of students in the subject at senior secondary school external examinations, moral decadence among students resulting to instability retarding national development. Therefore, the concern was to assess the level of Islamic studies curriculum implementation in senior secondary schools in north West Geo-political zone, Nigeria. To achieve that, Five (5) research objectives were set, which aimed at assessing the role of teachers' qualification the influence of adequate and appropriate instructional materials, influence of class size/ population the role of supervisory activities and the influence of scope and level of difficulty of contents in ensuring effective implementation of Islamic Studies curriculum content at senior secondary school level in North-West zone, Nigeria. The study raised five (5) research questions and five (5) research hypotheses which are in line with the research objectives. Appropriate literature reviews were of both conceptual and theoretical framework for the study was built on the theory of system approach. The research adapted descriptive survey design and used two instruments; a questionnaire and structured interview. The target population was) seventeen thousand six hundred and forty,(17640) while the sample size was 1,740 comprising teachers, principals, supervisors and directors of Ministry of Education. These groups responded to the questionnaire and structured interview. The research information from the questionnaire were collected and analyzed using descriptive statistics such as standard deviation, means and percentages. The non- parametric statistics Kruscal Wallis was used to test the five hypotheses. The structured interview was subjected to chi-square statistical analysis. The outcome of the hypotheses tested at 0.05 level of significance revealed that the five (5) null hypotheses were rejected. The study revealed that, teachers teaching Islamic Studies in most secondary schools in North West zone were not professionally trained to teach the subject. There were also inadequate instructional materials in schools and learning facilities were found to be grossly inadequate, overcrowded classroom was also discovered. There were also poor supervisory activities by the ministry of education officials. It was also discovered that the scope of the curriculum content is wide and exhibit high difficulty to students in senior secondary schools in the study area. The study recommended that qualified teachers should be employed to teach Islamic Studies, effective supervision should be put in place and there is need for review of the entire curriculum contents in order to address the issue of wide scope and to simplify the difficult topics in the curriculum contents.