This actual research investigated the relevance of information related to proven reserves of oil and accounting information (net income and book value) disclosed by oil companies. Thus, by means of a value relevance study applied to the global petroleum industry, the following question resulted from the research problem: What relevance does information related to proven reserves of oil and accounting information (net income and book value) disclosed by integrated oil companies that are listed on the stock exchange in New York (New York Stock Exchange-NYSE), during the period 2001-2012, have? To answer this question and achieve the proposed objective there were applied panel data regressions in a sample of 15 oil companies, each company with observations for 12 years, totaling 180 observations. There have been tested 8 models, each of them having as dependent variable the Naperian or natural logarithm (ln) of the average share price, considering the closing prices of November, December, January and February. As independent variables have been tested book value (PL), net income (LL), capitalized costs (CC), volume of gas and oil reserves (RPO&G), components of the change in reserve value, discounted future cash flow (FCD) of the reserves. The results revealed that the information about PL is more relevant than the information about LL. The information about the capitalized costs is relevant, with a strong inverse negative relationship with the share prices. Further, the results demonstrated a weak relevance of information on the volume of gas and oil reserves and the discounted future cash flow of the reserves. When broken down into its main components (reviews, recovery improvements, discoveries, purchases, sales and production), the information about volume of gas and oil reserves gained in relevance. Specifically, there has been observed a considerable relevance of information about discoveries, production and the purchases of oil and gas. Lastly, the results indicated that the market value of oil company is a function of PL variable and accounting information relating to proved oil and gas. These findings reinforce the idea that the accounting data are incomplete information for determining the value of an oil company, as the information related to proven reserves of oil and gas contribute to an increasing relevance of the measured accounting variables in historic values. As a result, additional information in the note about the reserves of oil is relevant and necessary, beyond the traditional remarks disclosed in the financial statements.