peer reviewed ; This paper presents the dialect classifications for Luxembourgish. The first dialectological studies regarded the Luxembourgish dialect(s) as embedded into a larger ‘German’ spectrum of varieties, but from the 1960s onwards the state border in the east with Germany was conceptualized more and more also as a linguistic border. The first classification of Luxembourgish by Hardt (1848), with four dialect groups, was rather impressionistic. The classifications from the 20th century are based on survey data. The first two are in the framework of spatial dialectology, the third one is a dialectometric study. Bach (1933) did not present subdivisions, but on the basis of the isogloss maps at least three groups show up. Bruch (1954) identified four dialect regions. Schiltz’s (1997) quantitative analysis merges two of these regions. There are no classifications in the field of perceptual dialectology.