Diffuse scattering from crystalline structures with quantum dots (QDs) in the shape of a regular truncated pyramid with a square base is investigated. The elastic strains around QDs are calculated using the Green function method. The fields of the QD atomic displacements and the angular distribution of scattering intensity in the reciprocal space as functions of the QD concentration are simulated numerically. The influence of a pyramidal QD cross section by the diffraction plane on the diffuse X-ray scattering is demonstrated.