A geographical forwarding algorithm is an attractive localized data forwarding scheme for wireless sensor networks (WSNs) due to its directional routing properties and scalability. Also, the inherent constraints of WSNs such as limited battery power and network resources require the simplicity and energy efficiency of protocols. In this paper, we propose a Time Backoff-based energy-efficient Geographical Forwarding (TBGF) for WSNs. TBGF is a combined MAC and routing protocol based on geographical forwarding that achieves energy efficiency and minimization of control overhead. TBGF uses the energy-aware time backoff scheme with the optimal geographical information to make the next forwarding decisions. Our simulation results show that the proposed protocol outperforms other existing schemes in terms of energy efficiency and network performance.