The structure of poly(chloromethylsilane-co-styrene) obtained from styrene and chloromethyldisilanes is investigated by HR liquid and solid-state NMR techniques. H-1-C-13 DEFT and H-1-Si-29 HMBC investigations indicate that the system has to be considered as a polymer blend consisting of poly(chloromethylsilane) and polystyrene. Differences in the mobility of the two polymers are demonstrated by 1H-13C WISE spectroscopy. The results of spin diffusion investigations carried out on poly(chloromethylsilane-co-styrene) samples indicate surprisingly small polystyrene domains.