This paper analyzes the institution of suretyship in the German and Polish legal systems. It highlights both differences and similarities of the main characteristics, such as conditions to validity, scope of liability, defences available to the surety and the recourse by the surety in case of payment. The analysis is based not only on the relevant legal provisions, jurisprudence and doctrine, but also on their application in the business practice of the two countries.The comparative overview of the suretyship permits the conclusion that both legal systems regulate the principal features of this institution rather similarly. However, there are also a number of significant differences. Notably, German jurisprudence and doctrine appear to adopt a more flexible approach to this institution than the prevailing position in Polish law. On the other hand, the liability of the surety is more rigorously shaped under Polish law. Whereas German law and practice seem in many respects to be more protective of the surety than Polish law and jurisprudence, the latter provides the surety with far less possibilities to be released from the assumed liability.