The paper focuses on the lost Shrovetide songs by Arian preacher and writer Jan Stoiński. They were still known in the times of F.S. Bock or K. Sandius, but subsequent historians and bibliographers only researched them on the basis of the works of their predecessors. They have recently been discovered in Andrzej Lubieniecki’s silva rerum (manuscript of the Remonstrant Library 527, p. 682–691). The songs were probably written down in Lubieniecki’s book several years before 1667 and given the title indicating the detailed circumstances of the works’s creation: in 1667, in Lithuania, Łostaje estate – the property of “Mrs. Koszkielowa” (Kosküll, Koschkull), who went on to marry Albrycht Arciszewski; the songs were written in reaction to the drunkenness of “Mr. Wolan,” an Evangelical Christian. Pieśni mięsopustne is composed of six stichic poems in octosyllabic verse, written in preacher-like rhetorical form. Song I constitutes an introduction, with the poet addressing “Christians living in excess” and announcing that his mission is to remind them that eternal happiness needs to be earned through virtuous conduct and good deeds and to warn them not to engage in devious speculation or abuse God’s mercy. The songs include references to Shrovetide customs, especially through harsh criticism of alcohol abuse. An important element of their persuasive character consists in debunking the arguments of sinners attempting to make excuses for their wrongdoings (e.g. by referring to the figure of the Penitent Thief), which is accompanied by condemnation of bad attitudes, preaching, and calling for repentance. Interestingly, despite criticism aimed at the Catholic approach to fasting, the songs do not condemn or scold any particular denomination.