The geographical distributions, in the form of mosaic maps, altitudinal ranges, frequencies, and habitats of 29 Sphagnum taxa known to occur in Switzerland are described. The detailed distribution patterns vary among individual taxa depending on their habitat requirements. Sphagnum fimbriatum is confined to lowlands in the north and north-west of the country. Similarly, S. cuspidatum, S. rubellum, S. squarrosum, and S. tenellum are more common north than south of the Alps while the occurrences of S. platyphyllum show a southern tendency. S. capillifolium and S. magellanicum are the most frequent taxa, followed by S. compactum, S. russowii, and S. subsecundum whereas S. molle, S. subfulvum, and S. affine are known from four or fewer localities. Taxa with a narrow vertical range are in general ecologically more restricted than taxa which are widely distributed with respect to altitude. Peat mosses do not occur in the northern, north-western, and southernmost lowlands, nor in the Central Alps due to climatic reasons, and have disappeared from the Plateau mainly because of wetland drainage and fertilization in the course of increasing agricultural intensity. Most Sphagna have probably declined as a consequence of habitat loss and/or degradation, and from a national viewpoint, many taxa are nowadays considered to be threatened in Switzerland.