This article reports the performance of 15-year-old Hong Kong students in mathematical literacy in an international study called PISA 2000, in which Hong Kong has topped the list of 41 participating countries/regions, with a mean score significantly higher than all other countries except Japan and Korea. With the conceptual framework developed by PISA for the assessment of mathematical literacy, this survey on students’ mathematics achievement is rather different from other international studies in that it focuses on students’ competencies in applying knowledge and skills to understanding and solving problems and to making informed judgments and decisions in real-life situations. As PISA 2000 did not collect data related directly to classroom teaching and therefore could not provide an explanatory framework, it is speculated that the exceptionally good performance of Hong Kong students in PISA mathematical tasks may be attributed to their strengths in the basics of algebraic and geometric manipulations, as evidenced in previous international comparative studies. This article begins with a brief introduction to the rationale and general design of PISA and a detailed delineation of the conceptual framework of mathematical literacy. The overall performance of Hong Kong students, including gender differences, relative to the international mean performance will be outlined and analyzed in terms of different attributes of the PISA framework for mathematics. The final section discusses these PISA findings and derives some general implications for mathematics education in Hong Kong.