The agronomical potential and the phytochemical variability of 18 genotypes of the Paraguayan plant Stevia rebaudiana have been investigated in Switzerland in order identify the best genotype for local cultivation. Over a two years period, yields in dry leaves ranged from 10 to 170 g m-2, with a percentage of leaves ranging from 53 to 75 %. HPLC analyses showed a notable variability in phytochemical composition, with stevioside content ranging from 0.3 to 7.9 % w/w and rebaudioside A from 0.3 to 6.5 % w/w. Cultivation of S. rebaudiana in Switzerland is feasible. With a density of 10 plants per m2, the potential yields of dry matter are approximately 1-2 t ha-1. The most productive genotypes (Pharmasaat, Hem Zaden, Stepa and Mediplant 3 and 11) will be submitted to the industry for organoleptic evaluation.