This review shows that the measurement of viscoelastic properties is a powerful tool in the study of thermoreversible gels. Although many conclusions may be drawn about network development and its structure, it is also shown that the use of additional techniques (e.g. small angle S-ray and neutron scattering techniques and optical rotation) and the combination with thermodynamics and network models, widens the insight in the crosslinking process and the gel structure temendously. A general Introduction is followed by eight Chapters concerning synthetic polymers (PVC, PVAL, PMMA, PS, PAN, PE,...