Nowadays, it is generally accepted that the production of biofuels through the pyrolysis of lignocellulosic biomass may be an interesting alternative to fossil fuels. The appeal of this renewable resource is due to its worldwide availability and its environmentally friendly nature. The liquid fraction obtained from pyrolysis processes, bio-oil, is the most valuable product given its further application as biofuel, although it contains many oxygenated compounds and has a low heating value and high acidity, which hinders its direct application or even storage. To improve its quality, a dual strategy combining the two well-known upgrading approaches of cracking catalyst addition and waste plastics co-feeding has recently emerged as a promising solution since positive synergistic effects are achieved that are more suited to the production of upgraded biofuels. The upgrading reaction mechanism has mainly been associated with the presence of plastic wastes, which serve as H 2 donors to promote hydrocracking and hydrodeoxygenation catalytic reactions, and accordingly, highly significant results have been achieved using this dual strategy. This chapter discusses the most important of these results as reported in the literature obtained in facilities ranging from thermogravimetric reactors (technology readiness level (TRL) 2) to pilot plants in a relevant environment (TRL 5).