The aim of this study is to investigate the laws that govern the relationship between maximum total fibre stresses and geometric parameters-in particular, thickness t-for open thin spherical shells loaded symmetrically with respect to their axis of revolution. For this purpose, closed-form expressions defining the net stresses in such shells are derived on the basis of a simplified-but nevertheless sufficiently accurate-theory for non-shallow shells of revolution. For some of the more commonly encountered loadings and various support boundary conditions, these expressions give the total stresses explicitly in terms of geometric variables and Poisson's ratio v in a form that brings out clearly the contribution of the bending-disturbance component. The influence of these geometric variables upon the peak (total) stresses in the shell is discussed, with special emphasis on the effectiveness of thickness-increase in reducing such stresses.