Advances in the areas of QoS and IP multicasting have necessitated the need of integration of these two important features of Internet. Differentiated services (DiffServ) has been proposed as a scalable solution for supporting QoS in the Internet. Coexistence of multicasting and DiffServ is promising since the DiffServ model can provide a scalable framework and may reduce the computational complexity to locate a QoS-satisfied multicast tree. We first identify the problems of provisioning multicasting in DiffServ domains. Next, we propose an efficient DiffServ-Aware Multicasting (DAM) scheme which has three novel features: weighted traffic conditioning (WTC), receiver-initiated marking (RIM) scheme, and Heterogeneous DSCP Headers encapsulation (HDE). The proposed technique solves many problems with the integration of DiffServ and multicasting while accommodating heterogeneous QoS requirements. The framework is scalable, flexible, and feasible. Performance evaluation through analyses and simulations demonstrate conformance of the QoS requirements and the potential benefits of DAM.