Nagana szlachectwa (Latin: 'Vituperatio nobilitatis'), literally reprobation/reprimand/censure of nobility, also translated by Norman Davies as Test of Nobility^[1] was a legal procedure of the revocation of nobility in the Polish–Lithuanian Commonwealth.

Due to the absence of formalized heraldry laws and lineage in early Poland, nobility of a person was tested in a regular court.^[2] The confirmation of nobility was based on calling for a certain number of witnesses. In Poland this was in accordance with the 1633 statute,^[3] in Lithuania by Chapter 3, Article 22 of the 1588 Statute.^[4] The latter demanded two witnesses each from the maternal and paternal side. The penalty for perjury was being stripped of one's own szlachta status, by the Constitution of 1601.^[5]

In case of the successful nagana, the accuser earned up to half of the property of the accused,^[6] with the other half going to the state.^[7] The justice was highly prone to miscarriage, in particular, to abusive ennoblement^[8] Therefore, this procedure was gradually restricted in various ways. After 1581, the procedures took place before either the Crown Tribunal or the Lithuanian Tribunal.^[9]

Norman Davies conjectures that this practice was among the factors leading to the establishment of a unique Polish practice of heraldic clans.^[1] It is also asserted that this practice led to development of extensive personal archiving and archive research among Polish nobility.^[6]

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