The survey was conducted in 2022 among 690,000 students in 81 countries worldwide, and in Croatia it was carried out in March and April 2022 in 178 secondary schools and two primary schools among 6,135 15-year-olds.
Broken down by the type of school, students in grammar schools fared better than those in vocational schools.
Concerning mathematical literacy, Croatia ranks 36th on the list of 81 countries, said the head of the National Centre for External Evaluation of Education, Vinko Filipović, on Tuesday.
He said that this gap between Croatian students' performance and the OECD average in mathematical literacy has been reduced in the latest survey.
Singapore, Macao (China), Chinese Taipei, Hong Kong (China), Japan and Korea (in descending order of average scores) outperformed all other countries/economies in mathematics.
In Europe, Estonia is the best performer.
Some of the countries that performed worse than Croatia when it comes to mathematics are Iceland and Israel, Greece, Romania, Bulgaria and Serbia.
Reading literacy
Croatians rank 26th in reading literacy, and apart from Croatia some other countries within the OECD average are Latvia, Spain, Norway, Portugal, Belgium, Germany, Austria, France, Israel, Hungary and Lithuania.
Girls outperform boys in reading literacy in Croatian schools.
Scientific literacy
Croatia is also within the OECD average when it comes to scientific literacy.
It ranks 31st, and in the latest survey, Croatian girls outperformed boys in this segment, too.
In Europe, Estonia is again the best performer. Worse than Croatia are Norway, Italy, Israel, Slovakia, Serbia, Montenegro, Kosovo, etc.
PISA stands for OECD's Programme for International Student Assessment.