The structure of mesomorphous elastomers, made of cross-linked side-chain liquid crystal polymers, is investigated by small-angle neutron scattering. Three types of samples are synthesized in the presence of deuterated toluene, one without mesogenic groups (C) and two with different proportions of pending mesogenic side chains (A and B). SANS is measured at the preparation concentration state and at maximum smelling, in equilibrium with deuterated solvent. These experiments give a test of the homogeneity of cross-linking. Samples carrying bulky mesogenic side groups (A and B) appear to be less heterogeneous than the corresponding mesogen-free network (C). Results are discussed in terms of mesomorphous interactions which are still present at the preparation swelling ratio and in terms of a steric effect due to the side chains, which prevents chains from interpenetrating and entangling.