When the OECD released the results of PISA 2025 on September 8, 2026, eight Southeast Asian countries received another snapshot of how their students perform in science, reading, and mathematics. Laos, Myanmar, and Timor-Leste did not participate in this cycle.
The results show a region moving in different directions. Science scores ranged from 560 in Singapore to 373 in the Philippines, while some countries recorded sharp gains and others experienced declines.
Here are the eight Southeast Asian countries that took part in PISA 2025, ranked by their science scores, the main domain assessed in this cycle.
Note: Science rankings are based on 91 countries and jurisdictions. Reading and mathematics rankings are based on 90, as the OECD excluded Uzbekistan from both domains due to inconsistencies identified in responses to its test instruments.
1. Singapore
Singapore recorded scores of 560 in science, 563 in mathematics, and 535 in reading. In science and mathematics, it was surpassed only by China’s B-S-J-Z system, comprising Beijing, Shanghai, Jiangsu, and Zhejiang. In reading, the OECD identified Singapore as the highest-scoring system in the world, ahead of B-S-J-Z China as well as Hong Kong and Macao.
Singapore was also the only Southeast Asian country to score above the OECD average in all three domains. The OECD averages were 482 for science, 461 for reading, and 463 for mathematics, highlighting the gap between Singapore and the rest of the region.
2. Viet Nam
Viet Nam scored 457 in science, 443 in mathematics, and 392 in reading. However, these results cannot be directly compared with previous cycles because Viet Nam used computer-based testing for the first time in 2025, after previously using a paper-based instrument derived from PISA 2012.
Because the change in format introduced methodological uncertainty, the OECD excluded Viet Nam from its trend analysis. There is therefore no official basis to conclude whether its performance has improved, declined, or remained stable compared with PISA 2022.
3. Brunei Darussalam
Brunei recorded a science score of 439. The publicly available summary does not provide its full mathematics and reading scores, but Brunei was reported to rank among ASEAN’s top three in mathematics and science and second in ASEAN for reading.
More than 5,000 students from 55 secondary schools took part in PISA 2025 between April and May 2025. The results placed Brunei among the region’s stronger performers, although it remained some distance behind Singapore.
4. Thailand
Thailand recorded one of the clearest improvements in the region. Its science score rose 23 points from PISA 2022 to 432, while mathematics and reading each increased by 13 points, reaching 407 and 392 respectively.
The OECD listed Thailand among just 11 countries and jurisdictions worldwide that recorded a significant improvement in science. Its scores remained below the OECD average in all three domains, but the results point to a shift after years of stagnation.
5. Malaysia
Malaysia saw modest gains in science and reading, reaching 419 and 393 respectively. Mathematics, however, fell 11 points to 397, continuing a longer decline from 440 in 2018.
The sharpest change appeared in basic mathematics proficiency. The share of students performing below Level 2 rose from 41 percent in 2022 to 65 percent in 2025, meaning nearly two-thirds of 15-year-old students had not reached PISA’s basic competency threshold.
6. Indonesia
Indonesia recorded six-point gains in science and reading, reaching 389 and 365 respectively. Mathematics moved in the opposite direction, falling two points to 364, placing Indonesia 73rd out of 91 countries for science, 74th out of 90 for reading, and 78th out of 90 for mathematics.
PISA 2025 in Indonesia involved 14,168 students from 419 schools. The sample represented around 3.9 million students, or 90 percent of the population aged 15 to 16.
7. Cambodia
Cambodia scored 382 in science, 366 in mathematics, and 347 in reading. Although all three remained well below the OECD averages, its gains since 2022 were among the largest in the world, with science rising by around 35 points and mathematics by 29 points.
The increase in mathematics placed Cambodia first among 46 countries and jurisdictions for improvement between 2022 and 2025. Compared with 2018, its science score rose by 52 points, mathematics by 41 points, and reading by 26 points.
8. Philippines
The Philippines recorded gains across all three domains, with scores of 373 in science, 371 in mathematics, and 367 in reading. All three were the country’s highest scores since it first took part in PISA in 2018.
The improvement moved the Philippines out of the bottom ten countries. Its 20-point gain in reading also made it the fastest-improving country in the domain, according to the OECD.
What Does This Mean for Southeast Asia?
PISA 2025 shows a region with a wide performance gap and sharply different trajectories. Singapore remains far ahead, Thailand, Cambodia, and the Philippines are showing improvement, while Malaysia and Indonesia continue to face pressure, particularly in mathematics.
At the same time, average reading and mathematics scores across OECD countries continue to decline. Southeast Asia is facing the same global challenge, but from very different starting points and with very different rates of change.
