The Programme for International Student Assessment (PISA) evaluates 15-year-olds’ ability to use their reading, mathematics and science knowledge and skills. Since 2000, Switzerland participated in every PISA cycle conducted by the OECD. At the end of every cycle, the Swiss PISA data of the national 15-year-old sample has been made available in the international data sets published on the OECD website. Before 2015, in addition to the sample of the 15-year-olds, an additional and larger sample of 9th grade students was drawn and tested in Switzerland. The resulting Swiss data for the 9th grade students, that allowed comparisons selected cantons, was published in full on FORSbase. Since 2015, solely the national PISA sample from the population of 15-year-olds is tested, that allows comparisons between three Swiss language regions, but not anymore between selected cantons. Thus, starting with PISA 2015 the Swiss PISA data are almost completely available in the international data sets published on the OECD website. However, the present dataset complements the international PISA 2018 dataset with some for the Swiss context relevant additional information as well with some national options from PISA 2018.