Hungarian sociolinguistic research began in the Linguistics Institute of the Hungarian Academy of Sciences in 1985. This research program soon expanded to embrace the Hungarian communities in the countries bordering Hungary. Unlike all previous research in Hungarian linguistics, this program aims to survey the language use of 10 million Hungarians in Hungary and 3 million bi- or multilingual Hungarians in the neighbouring countries. In this paper, three major projects are briefly discussed: the Hungarian National Sociolinguistic Survey, the Budapest Sociolinguistic Interview, and the book series “The Hungarian Language in the Carpathian Basin at the End of the 20th Century”.