Biodiesel is being considered as a renewable fuel candidate to completely or partially replace fossil diesel. Understanding its combustion is key to assess its applicability in practical compression ignition engines. Significant progress has been made in understanding biodiesel combustion through experimental studies, development of reaction kinetics to describe its oxidation, and simulations in typical engine environments. The use of surrogates in place of the real biodiesels plays a crucial role in this endeavour. This chapter reviews the existing studies revolving around surrogate fuels for biodiesels. Thereafter, the challenges ahead in this context to further enhance our knowledge of biodiesel combustion are presented, and possible options to address these are discussed where appropriate. © 2017, Springer Nature Singapore Pte Ltd.