Exorcisms, spells, medical prescriptions -combined with astrological phenomena and accompanied by words, phases and magic signs and various blessings are texts often occurring in Byzantine and Post-Byzantine manuscripts. Deeply rooted in antiquity, they have survived and have remained alive even today. Undoubtedly, they represent a most tempting challenge for research as regards their philological, historical, religious and anthropological aspect. Samples of such texts from three Post-Byzantine manuscripts have been selected and are presented in this article; they refer to the relations between men and women, to the social relationship of humans, such as friendship, hatred, law-suits, as well as to various illnesses, such as jaundice and fever. A selection of Church canons, condemning both the performance of magic acts and the recourse to them is also presented.