Biogas from anaerobic digestion (AD) has been identified as an important source of clean energy that can make a contribution towards renewable energy provision in order to mitigate climate change. Many of the crops and agricultural residues used in today’s AD systems consist primarily of lignocellulosic materials. The efficiency of conversation of these feedstocks to biogas have been shown to be improved through the use of physical, chemical or biological pre-treatments. The benchmarking of commercial biogas plants through-out Europe demonstrated several challenges that need to be addressed to further optimise biogas yield and to improve its overall economics. Central to this is the need for more efficient release of sugars from recalcitrant lignocellulose feedstocks. In this review we discuss AD and assess the use of pre-treatments for improved production of biogas from agricultural residues and crops.