The invention relates to industrial gear oil compositions that have been specially designed to have improved friction and/or antiwear properties. That is the industrial gear oil compositions of the invention provide good performance and/or protection in the areas of friction and/or antiwear due to the use of a synergistic combination of additives. The industrial gear oil compositions of the invention utilize a combination of certain phosphorus-containing compounds and derivatives of a hydroxy-carboxylic acid, to provide a synergistic improvement in friction and/or antiwear properties.