Over the last decade a number of schools have developed integrated business programs. This study aimed to identify this approach to the implementation of Integrated Business Studies curriculum in secondary schools in Kenya. Business Studies had undergone some changes in recent past in an attempt to improve quality of performance. The 2002 syllabus review was intended to be an improvement of the 1984/85 syllabus introduced during the 8-4-4 system of education. The innovation gave birth to the Integrated Business Studies syllabus in which Commerce, Accounting and Economics were integrated to be taught as a single subject. The study investigated the rationale for the integration of Commerce, Accounting and Economics in secondary schools; examined the implementation of integrated Business Studies; and suggested ways in which Business Studies can arouse the interest of both learners and teachers in secondary schools. The curriculum development model developed by Ralph Tyler (1949) formed the main guiding theme in this study. However, the ideas of Taba (1962) and Wheeler (1967) will be incorporated in the discussions. The study employed a descriptive survey research design. There were 49 secondary schools with 589 teachers and 11245 students in Kajiado County. The study selected 10 schools representing 20% of the schools in the district with 200 students, 10 principals and 14 teachers of Business Studies. Questionnaires, interview schedules, participant observation and document analysis were used to collect data. Data were analyzed using statistical package for social sciences (SPSS) and descriptive statistics. Data were reported as frequencies and percentages. The study established that teachers lean heavily on textbooks and teacher-centered teachinglearning strategies that limited students‟ participation in class hence the poor performance. It was also noted that most teachers of Business Studies were not adequately trained and in-serviced since one was either trained in one or two of the integrated subjects making it difficult to teach Business Studies as a whole. Other subject teachers contributed greatly towards the negative attitudes that students had towards Business Studies hence only a few pursued it in Forms Three and Four. Recommendations were made based on the findings. It is hoped that findings will help provide data to assist Business Studies curriculum developers and planners so that they may be able to continue revising future syllabi, while bearing in mind the students‟ and teachers‟ attitudes towards this integrated syllabus and effects of these on their performance. The other groups to benefit would include: the teacher trainers and the quality assurance and standards supervisors.