In this paper, I will show that the investigation of passive constructions by means of written questionnaires ('Projekt Dialektsyntax des Schweizerdeutschen', University of Zurich) provides reliable data on Swiss German dialect syntax. Concerning the accusative passive, I will illustrate that the auxiliaries 'kommen' or 'werden' and inflected or uninflected past participles are found in geographically distinct areas. Our material shows a similar geographical distribution of variants as the data from traditional direct interviews. Since we have been working with several consultants at each place, it is possible to give a picture of the gradual nature of the transition from one to another variant. The distribution of the passive constructions fits more general, North-South-oriented dialect-geographical patterns (cf. Hotzenköcherle 1986) that are well-known from other syntactic phenomena (such as the inflection of the predicative adjective (SDS III 256), of copredicative and resultative constructions (Bucheli Berger/Glaser (2004), Bucheli Berger (2005)). The evidence concerning the dative passive (recipient passive) leads me to the conclusion that its existence is not beyond any doubt in Swiss German. Beside the different passive constructions, I will also discuss the geographical distribution of alternative constructions such as active, 'tun'-periphrasis, etc.