In the framework of the geometrically nonlinear 6–parameter resultant shell theory we give a characterization of the shells without drilling rotations. These are shells for which the strain energy function W is invariant under the superposition of drilling rotations, i.e. W is insensible to the arbitrary local rotations about the third director d3. For this type of shells we show that the strain energy density W can be represented as a function of certain combinations of the shell deformation gradient F and the surface gradient of d3, namely . For the case of isotropic shells we present explicit forms of the strain energy function W having this property.