(Polish title below: Matka i syn - wplyw Barbary z Tarnowskich Zamoyskiej na proces wychowania i wyksztalcenia Tomasza Zamoyskiego w swietle korespondencji z lat 1605-1610). Tomasz Zamoyski (1594-1638), son of Lord Grand-Chancellor of the Crown and Grand Hetman of the Crown Jan Zamoyski, from his eighth birthday stayed in Zamosc, where he learned from especially chosen preceptors at the Academy founded by his father. When in 1605 Hetman Zamoyski died, Barbara z Tarnowskich Zamoyska (1566-1610) became the main guardian of her son. The article discusses the issue of Barbara Zamoyska's influence on her only son's upbringing and education. Although in the years 1605-1610 the widow-mother lived in Krzeszow, she kept sending her son letters. They can be found in Zamoyski Archives files of the Central Archives of Historical Records. The letters were usually divided into several sections. Moral and educational advice in variably constituted an important part of the text. Barbara Zamoyska's great love towards her son and her care about his health and composure are very conspicuous in the correspondence. She appeared to be an extremely emotional figure - mother-guardian, putting great emphasis on formal religious practice - not only public nut also private. There are also sporadic remarks or rather suggestions pertaining to Tomasz's educational upbringing. The fact that they occur only incidentally proves that she did not interfere too profoundly with the educatio nal process of her son. In this matter she relied on his teachers and guardians. Summing up, Barbara Zamoyska's correspondence constitutes valuable material for research on women's mentality and spirituality in the Old-Polish epoch. It is also a vital source of knowledge about upbringing of magnate children and of family relations in the Old-Polish times.