Riemannian superspaces of minimal dimensionality

Superspaces with dimensionality $n=n_b+n_f$, where $n_b$ is the dimensionality of the Bose coordinates and $n_f$ is the dimensionality of the Grassmann coordinates, are classified. It is shown that Einstein superspaces with dimensionalities $(n_b,n_f)=(0,2)$, $(0,4)$, $(1,2)$ are spaces of constant curvature.