The aim of this study was to analyse the determinants of the indebtedness of companies in the Brazilian telecommunications sector in the light of the Static Trade-Off Theory (STT) and the Pecking Order Theory (POT). The methodology used was multiple regression analysis with panel data for the period from 2002 to 2013, using short-term debt and long-term debt as dependent variables, and profitability, tangibility, growth, size and risk as independent variables. The results showed a negative relationship between the profitability, size and risk variables for short-term debt, and a negative relationship between size and risk for long-term debt.