The crosslinked copolymers of N-vinylpyrrolidone with 1,4-(N,N-bismaleimido)benzol and with trimethoxyvinylsilane were synthesized by free radical copolymerization. The copolymers were characterized by FTIR spectroscopy and thermal analysis. The values of specific surface area and porosity of the copolymers were determined with use of low-temperature adsorption. Sorption capacity of the copolymers toward Re (VII), Mo (VI), and W(VI) ions was investigated and was found to depend strongly on the pH. A possibility to separate Re(VII) and Mo(VI) ions with use of the copolymers under investigation in their combined presence in neutral and alkaline media was shown. Moreover, in the conjoined presence of Mo(VI) and W(VI) ions at pH 5-14, tungsten(VI) can be separated from molybdenum(VI) with the copolymer of N-vinylpyrrolidone with trimethoxyvinylsilane. POLYM. ENG. SCI., 56:1303-1312, 2016. (c) 2016 Society of Plastics Engineers