In the last few years there have been great variations in prices of crude oil in the world caused by several reasons: wars in the Middle East, global economic crisis, the Iranian nuclear issue, workers' strikes on platforms, hurricanes that threaten oil rigs, etc. Consequently, the prices of petroleum products have significantly changed mainly increased. As people spend more on fuel, their purchasing power and standard are being reduced, resulting in weakening of their quality of life. The formula for calculating the price of petroleum products of the oil company INA, majority-owned by the Republic of Croatia, does not include the price of crude oil - the basic raw material for its production, but it includes the cost of petroleum products in the Mediterranean market. This creates the possibility of manipulating the price of petroleum products in order to achieve extra profits of oil companies. This paper examines a multiple linear regression model that will try to answer the question as to what extent the trend of crude oil prices on the world market, with USD to HRK exchange rate and VAT rate was statistically significant in the price of Eurosuper 95 in the Republic of Croatia in the period from January 2007 to February 2013.