The usage of hollow poly(styrenesulfonate)/poly(allylamine hydrochloride) polyelectrolyte capsules for the selective precipitation of YF3 from water solution was described. Weakly crystallized YF3 particles of 6-9 rim diameter were synthesized exclusively inside the restricted volume of the polyelectrolyte capsule and characterized by transmission electron microscopy, scanning electron microscopy, and wide-angle X-ray scattering methods. Fluoride loaded poly(styrenesulfonate)/poly(allylamine hydrochloride) capsules were shown to be an effective tool for recovery of Y3+ traces from water solutions with up to 99% yield of recovery. The influence of the initial concentration of Y3+ as well as of the concentration of attendant metals (Na+, K+, Sn2+, ZrO2+, Fe3+) on the recovery yield was also investigated.