Sorption properties of fibrous nitrogen-containing sorbents based on polyacrylonitrile containing diethyldithiocarbamate (TIOPAN-2) and 8-mercaptoquinoline groups (TIOPAN-6) with respect to the platinum(IV) chloride complex were studied. The effects of the temperature, platinum concentration, and acidity on the metal recovery were determined. The kinetics of sorption and sorption capacity of sorbents in hydrochloric acid and chloride solutions were established. The most probable mechanism of sorption and the composition of compounds formed in the fiber phase were proposed.