The transition metal dichalcogenides possess a layer structure, and are known to accept a wide variety of electron donor species between layers to form intercalation complexes. Three aspects of the magnetic properties of these systems are considered here. First, the changes in band paramagnetism that can be achieved by the increase in the host material conduction band filling on intercalation are considered. Second, carrier localization, and the formation of local moments, can be induced in systems with strong charge density waves distortions. The system 1T-TaS//2 plus hydrazine is discussed. Third, for the intercalaction complexes formed with the 3-d transition metals, the local moments present on the 3-d metal ions show a variety of magnetic ordering which are mediated through the conduction electrons in the host layers. Recent polarized neutron experiments are discussed.