The subject of this article is the hierarchy of the sin in the Middle Ages in Poland. According to this information Author conclude that denial of God’s unity and power, heresy, blasphemy, violation of Church’s property and privilege, killing, sin contra naturam (sexual), incest and adultery was recognised as the most serious sin. All this vices violated the order both divine and human. It destroyed stability and routine of the world. It was dangerous not only for the person who had done this but also for his brothers and for all communitatis christianae.