Considering the large number of dangers that we face on a daily basis, it is important to provide economic protection against these dangers, and there come insurance and reinsurance companies which make it easier and reduce the financial consequences of unlucky events. Insurance is a legal relationship based on contract and includes insurers, insured persons, insurance premiums, contractors, insurance compensations and insured risk. There are many types of insurance, life and non-life insurance, and one of them is liability insurance for the use of motor vehicles, which is also the most prominent in Croatia, so the emphasis will be on this type. The main purpose of this paper is to show the impact of the liberalization of the insurance market on the business of the four largest insurance companies according to the collected premium for motor vehicle liability insurance, and those are Croatia osiguranje d.d., Euroherc osiguranje d.d., Allianz Zagreb d.d. and Jadransko osiguranje d.d. The collected liability insurance premium for the use of motor vehicles at these insurance companies will be analyzed for the period from 2011 to 2015. Liberalization of the market in Croatia started because of the EU regulations which required adjustment of legislation of this area. As part of preparations for access in EU, Croatia adopted a legal framework in 2008, but liberalization begins in 2013 when it is launched by Generali osiguranje d.d. Liberalization abolished state control of insurance conditions and prices, and thus increased the bidder's competitiveness and provided the freedom to determine its own insurance premium tariff, which led to its decline.