We have investigated the elastic scattering of high energy Sigma(-) off ele
ctrons from carbon and copper targets using the CERN hyperon beam. Scatteri
ng events are identified using a maximum likelihood technique exploring the
kinematical relations of the scattered particles. The observed Q(2)-distri
bution of these events suggests a mean square charge radius of the Sigma(-)
of < r(ch)(2) > (Sigma(-)) = 0.91 +/- 0.32(stat.) +/- 0.4 (syst.) fm(2). T
his constitutes the first measurement of < r(ch)(2) > (Sigma(-)) and demons
trates the possibility to also measure the charge radii of other hyperons.