The present work focuses on the development of the exact geometry piezoelectric four-node solid-shell element based on the first-order 7-parameter equivalent single-layer theory, which permits to utilize the 3D constitutive equations. The term “exact geometry” reflects the fact that the reference surface geometry is described by analytically given functions, in particular spline functions, and displacement vectors are resolved in the reference surface frame. As fundamental shell unknowns, 6 displacements of the outer surfaces and a transverse displacement of the midsurface are chosen. Such choice of displacements gives the possibility to derive strain-displacement relationships, which are invariant under rigid-body shell motions in a convected curvilinear coordinate system. To avoid shear and membrane locking and have no spurious 0 energy modes, the assumed strain and stress resultant fields are invoked. It is noteworthy that the elemental matrices of the hybrid method developed require only direct substitutions, i.e., no expensive matrix inversion is needed and they are evaluated by using the 3D analytical integration.