With growing awareness of global warming and climate change crisis and increased efforts by global intergovernmental bodies promoting a switch to greener alternatives from petrochemicals, research into biomass as an alternate source for biofuels and chemicals has been on the rise. Pretreatment has proved to be a major bottleneck in utilizing biomass to its full potential. Many commercial plants for the production of biofuels are functional, albeit at a higher price than their conventional petrochemical counterpart. With a view to bringing down the cost of bioproduction, reducing waste generation and utilizing biomass to its full potential, a biorefinery approach similar to a petroleum refinery is being probed. Newer nonconventional pretreatment methods are developed for efficient breakdown of lignocellulose for better utilization as feedstocks for various manufacturing processes. This chapter aims to provide an overview of lignocellulose, its sources, composition and conventional pretreatment methods. It will further focus on the novel pretreatment methods being developed over the last decade regarding its scalability to commercial production, environmental impact and economics. It will further delve into the utility of the emerging pretreatment techniques in the biorefinery development of lignocellulose and the research gaps in the current technologies.