This study measures the mathematical abilities high school graduates' in Bahrain. Mathematical abilities encompass conceptual understanding, procedural knowledge and problem-solving skills in the five content domains which are Number and Operations, Algebra, Geometry, Measurement, and Data Analysis and Probability. While procedural understanding focusses on performing facts and algorithms, conceptual understanding reflects a student's ability to reason and comprehend mathematical concepts, operations and relations which will be helpful in solving non-routine problems. A test consisting of questions from the five content domains was administered to students where they demonstrated conceptual understanding and procedural knowledge which enabled them to solve problems in various real-life situations. Structured interviews were also conducted to test their mathematical abilities and suggest ways to improve proficiency in mathematics and eliminate misconceptions. The results show that conceptual understanding and problem-solving skills are positively correlated. This research also endeavors to correlate students' performance in this test with their high school GPA.