Biogas production via anaerobic digestion (AD) of waste is a very attractive, yet a challenging task. This mini-review focuses on the recent efforts done to explore the effect of various nanomaterials additives on the biogas production rate. The materials are classified into three categories: (1) metal oxides, (2) zero-valent metals, and (3) nano-ash and carbon-based materials. The positive and negative effects of such nanomaterials on the AD process and consequently on the biogas production are discussed. Also, future perspectives to increase the biogas production are listed.