In 1788, the Great Sejm went into session in Warsaw. The deputies arriving in the city were trailed by detachments of cooks, butlers, stable lads and servants of all ilk. In their wake came various vagrants and also Jews. All of them viewed the session of parliament as an opportunity to improve their fortunes. In addition, con artists and thieves also came to town. The late 18th century was also a period when, subject to meeting some conditions, the Jewish population could legally stay in Warsaw. Among the Jews, there were also some criminals. The author seeks to portray the Jewish underworld on the basis of testimony of the city's residents accused of various offences in the years 1788-1792.