Wireless multimedia sensor networking (WMSN) is an efficient technology and has been widely used in multimedia data transport and applications. The key to the success of multimedia data transport is the transmission quality. Real-time critical multimedia requires e ifficient routing for data delivery with guaranteed QoS. However, satisfying the stringent QoS requirements of multimedia transmission usually translates to high energy consumption. How to efficiently minimize the energy consumption while ensuring QoS requirements is an acute problem. Therefore, in this article, we call routing protocols that can balance out the trade-o between network lifetime and QoS requirements “green routing protocols.” First, a detailed survey of existing routing protocols for WMSNs is presented, which are classified into two categories based on network structures. Moreover, the performance of existing routing protocols is compared in detail. Finally, future research issues of green routing protocols in WMSNs are presented and carefully discussed.