The focus of this study was on the comparison of mathematics curricula of General Certificate of Education (GCE) Ordinary Level (O-Level) and Secondary School Certificate (SSC). The purpose of this comparison was to trace out the factors responsible for the shortcomings in instructional objectives, contents, approaches, methods of teaching and pattern of assessment in the local (SSC) system of education. The study was specifically focused on: (1) to compare and analyze the aims and objectives of teaching mathematics at SSC and GCE (O- Level); (2) to compare the contents of textbooks and question papers of SSC and GCE mathematics courses; (3) to critically compare the effectiveness of approaches and teaching methods applied in both systems; (4) to compare and analyze the assessment patterns in both systems.The population of the study was comprised of teachers, students, prescribed text books of mathematics taught at SSC and GCE (O- Level) and question papers of the examination boards of both systems. The overall size of the sample was of 300 teachers, 200 students and 20 subject experts. The sample included 180 teachers, 120 students and 10 subject experts from the SSC system whereas 120 teachers, 80 students and 10 subject experts from GCE system. An interview protocol and questionnaires were designed and administered. A content analysis was made to compare the contents of textbooks and question papers of the last 20 years (1994-2013) of Board of Secondary Education Karachi (BSEK) and Cambridge International Examinations (CIE). The quantitative data were analyzed using t-test. It was concluded that the implementation of mathematics curriculum is relatively more effectivein GCE (O-Level) than in SSC curriculum although no significant difference has been found in the methods of teaching in both systems. The key factors traced out as major contributors in this difference of effectiveness were: GCE teachers were found clear and well-informed about the expected aims and objectives of their curriculum while SSC teachers were not clear because they did not have access to the expected aims and objectives of their curriculum; GCE textbooks were found aligned withthe expected aims and objectives of its curriculum while contents in SSC textbooks were not found in support of some very important expected outcomes of curriculum such as logical thinking and systematic reasoning; the approach of GCE teachers regarding organization of the contents for teaching was found to some extent concentric (spiral) while SSC teachers were found adopting a topical approach; the focus of GCE system was found on depth in knowledge through rigorous practice while the focus of SSC system was found on memorization of factual and procedural knowledge through practice; GCE system was found using formative assessment (assessment for learning) more systematically than SSC system where focus was on summative assessment (assessment of learning), during internal school assessments; GCE system was more focused on application of knowledge versus dispensation of knowledge however SSC system was focused more on constant dispensation of knowledge than its application. The foundation of difference between the two systems was found in their methods of assessment. The question papers of GCE mathematics were based on the overall expectations of the curriculum whereas SSC papers coveredthe expectation of factual and procedural knowledge only. GCE papers consisted of application based questions with no question exactly the same as the ones in the textbooks whereas SSC papers were comprised of exactly same as the textbook questions; GCE papers have been found with no sectioning on the basis of topics whereas SSC papers were sectioned on the basis of different topics;no pattern of repetition has been found in GCE papers whereas in SSC papers, a clear pattern of repetition was found; it was found thatwhole syllabus is required to be done inorder to attempt the GCE paper completely,whereas the SSC paper could be completed even after skipping many topics from the syllabus. No discontinuation of mathematics has been found at school level in GCE system whereas in SSC system,a suspension of mathematics teaching for one complete year (during grade IX) has been observed. In the light of these conclusions, concrete recommendations were made.