Synthesis gas or syngas is an intermediate, which can be produced by gasification from a variety of carbonaceous feedstocks including biomass. Carbon monoxide and hydrogen, the main constituents of syngas, can be subjected to a broad range of chemical and microbial synthesis processes, leading to gaseous and liquid hydrocarbon fuels as well as to platform and fine chemicals. Gasification of solid biomass differs from coal gasification by chemical composition, heating value, ash behavior, and other technical and biomass related issues. By thermochemical pre-treatment of lignocellulose as the most abundant form of biomass, for example, by torrefaction or fast pyrolysis, energy dense fuels for gasification can be obtained, which can be used in the different types of gasifiers available today. A number of pilot and demonstration plants exist, giving evidence of the broad technology portfolio developed so far. Therefore, a syngas biorefinery is highly flexible in regard to feedstock and product options. However, the technology is complex and does not result in competitive production costs today. Added value can be generated by suitable integration of thermochemical, biochemical, and chemical processes.