Stanisław Kostka was born to a Polish noble family at Rostkowo in northern Mazovia. At fourteen he and his older brother Paweł were sent to study at the Jesuit Collegio Romano in Vienna (1564). The brothers shared a room in the boarding-house; Stanisław's intense piety, his frequent communions, and his refusal to participate in the boisterous student life of the older Paweł created perpetual conflict.
In December 1566, gravely ill in their boarding-house and refused permission by the Lutheran owner to see a priest, Stanisław in his fever experienced (he later said) the consoling intervention of St. Barbara — who appeared to him with two angels and gave him the Eucharist — and the Virgin Mary — who placed the infant Jesus in his arms with the command to enter the Society of Jesus. He recovered, but was again refused by his father (and by his Vienna Jesuit confessor, who feared his father's reprisals against the order) the chance to enter.
In August 1567, then sixteen, he simply walked out of his boarding-house and travelled on foot — over 350 miles — through Lutheran Bavaria to Dillingen, where he met Peter Canisius. Canisius sent him on to the Jesuit novitiate at Rome, where Francis Borgia received him on October 28, 1567 — his seventeenth birthday. He died at the Jesuit novitiate of Sant'Andrea al Quirinale on the feast of the Assumption, 1568, ten months after entering — repeating to the end his prayer to the Virgin. Canonized 1726 jointly with Aloysius Gonzaga.