Sociodialectological research on border dialects, viz. vernaculars spoken in localities near a political or national boundary, has some advantages over traditional dialect studies – especially when of a more rarely found cross-border design. Depending on the language situation on each side of the border, i.e. in two separate diasystems (cf. Goossens 2000a: 335), one observes constellations with different, similar or identical standard languages roofing equally different, similar or identical dialects, and this in a small-scale setting, i.e. in often comparable extralinguistic conditions. The reported study investigates functional and structural dialect change at the Dutch-German border (Low Saxon dialect area), using proficient but all the same “natural” dialect speakers (N= 40) aged under 45 or over 55. In this article the outcome of the main linguistic hypotheses is discussed, presenting comparatively less structural levelling (Røyneland 2010: 261) in the German dialect. Functional loss, however, is proven to be smaller in the Dutch dialect. These findings are assumed to be connected with the varying standard-substandard constellations in the Dutch and German diasystems and their differing interference potentials. It is shown that dialect loss and regiolectization, even when attested in nearly identical dialects, evolve dissimilarly on both sides of the border. Next to this the article also provides an overview of the amount and quality of levelling products found in the informants’ speech.