Saint Euphrosyne of Polotsk is one of the major female figures of the 12th century in Kievan Rus. Hagiographical texts written in the honour of her depict the nun as wise as well-educated; she is called to have copied religious books, maybe founded a studium and taught sisters in monastery. Anyway, since no literary document demonstrating her knowledge of books is today at our disposal, her cultural activity seems far from being sure, even if we take into consideration the problems in saving libraries and literary heritage linked to the tatar joke. Recent interesting icongraphic studies on the paintings of the Saviour church in Polotsk, founded by Euphrosyne, revealed unexpected evidence of her erudition, allowing to name the books that most likely were at her disposal. The paper aims to sum up the most significant results of these studies, commenting their cultural significance in Medieval Europe.