The main aim of this research is to assess the effect of corporate characteristics on the level of management approach disclosure of Global Reporting Initiative in sustainability report by mining companies in Ghana. The study adopted content analysis method to assess the level of Global Reporting Initiative management approach disclosure in the annual sustainability reports. A sample of fifty (50) annual sustainability reports of ten (10) large commercial mining companies in Ghana from 2008 to 2012 were collected from the official website of the mining companies. Simple correlation and regression analysis using panel data models were conducted to test the research hypotheses in order to evaluate the outcomes. The findings indicate that size (positive), gearing ratio, working capital ratio and complexity (negative) are significant in all the dependent variables with profitability and age having effect on economic and environmental disclosures. It also reveals that growth and efficiency are insignificant in explaining the level of management approach disclosure of sustainability reports.