Abstract Language variety and educational achievement of indigenous primary school pupilsThis article explores the relations between language and mathematics test performance and a range of language related characteristics. The sample consists of 3,639 grade 2 pupils from 437 Dutch primary schools. Data were collected in 2014. The main question is whether pupils who speak Standard Dutch at home perform better than pupils who speak Frisian, a Dutch regional language or dialect. Results of the present analyses were compared with those from analyses performed on similar data collected in 1994. Between 1994 and 2014 the share of children who mostly speak standard Dutch with their mother and father has increased with 8 percent points to 95 percent. The share of mothers and fathers who mostly speak standard Dutch to each other has increased with 17 percent points to 91 percent. No correlation was found between language choice, i.e. speaking Standard Dutch or speaking Frisian, a regional language or dialect, and language and mathematic test performance. One remarkable finding was that children from the province of Limburg perform well while they speak Standard Dutch least.