This article is an attempt to introduce the problem of insurance fraud faced by Polish insurers during the twenty-year period between World Wars I and II. The author defines insurance fraud and posits causes of the origination of this phenomenon. It shows the influence of the economy on the insurance market and the interdependence between economic changes and the amount of insurance fraud. In the article, the author portrays the insurers’ struggles with different forms of fraud, most frequently arson with a goal of swindling compensation. In addition to theory, the author introduces a number of cases conducted by investigatory agencies and judicial courts regarding insurance fraud. A precise analysis is presented of the ways in which insurers guarded against payment of undue compensation, and the method in which they compensated for losses. Additional analysis is made of the criminal regulations operating in the inter-war period. The author also portrays the preventive measures taken by insurers along with firefighters and police who were specially prepared to fight against insurance fraud. Finally, an estimate is made of the economic consequences of insurance fraud, and the conclusion is made that on the one hand it is necessary to fight against insurance fraud with every possible means in order to limit its occurrence to a minimum, while on the other hand, it is impossible to completely win against the pathology existing in the insurance market.