Reverse logistics (RL) method is one of the most effective solutions to achieve sustainability in the construction industry. Many construction companies apply the method to adhere to regulations and build an environmentally friendly image for their business. Due to difficulties in carrying out RL operations and companies’ limited resources, they often outsource the RL work and concentrate on their core business activities. Strong relationships between construction companies and their reverse logistics service providers (RLPs) contribute to the positive performance of reverse logistics outsourcing. Previous studies have concentrated on outsourcing scope or selection of the most suitable RLP in the initial stage. There is little attention to relationship quality development between companies and their RLPs during the implementation stage to obtain the expected objectives of the outsourcing strategy. This study aims to explore the drivers of reverse logistics outsourcing relationship quality in the context of the Australian construction industry. Data of 173 construction practitioners collected from a questionnaire survey were analysed by Partial Least Squares Structural Equation Modelling (PLS-SEM) technique. The findings show that mutual goals, communication, flexibility, and outsourcing performance have significant effects on relationship quality. However, alternatives and relationship length do not impact relationship quality. Construction companies and RLPs can use these findings to manage outsourcing relationships better and achieve their reverse logistics goals.