This　study　examines　the　effect　of　project　manager　competencies　(communication,　teamwork,　attentiveness　and　managing　conflict)　on　project　success　with　a　mediating　role　of　project　knowledge　management.　We　collected　empirical　evidence　from　193-project　managers　through　a　structured　questionnaire　to　test　the　model.　Our　results　indicate　that　project　manager　competencies　significantly　contribute　to　project　success　and　knowledge　management　based　on　the　structural　equation　modelling.　Furthermore,　project　knowledge　management　fully　mediates　the　nexus　between　project　manager　competencies　and　project　success.　Our　research　recommends　organisations　emphasise　project　manager　competencies　(communication,　teamwork,　attentiveness　and　managing　conflict)　who　can　efficiently　manage　project　knowledge　and　subsidise　the　competitiveness　and　success　of　projects.