A method for producing high density fuels from isoprene which can be produced via biosynthetic routes using biomass sugars as feedstock. This allows for the production of isoprene and isoprene-derived fuels from abundant waste materials with the potential to significantly reduce DoD carbon emissions. Embodiments of the invention describe a method for conversion of isoprene to full performance jet and diesel fuels. Isoprene can be selectively oligomerized to generate a distribution of branched chain hydrocarbons. Combination of an oligomerization catalyst with a metathesis catalyst allows for the synthesis of high density cyclic fuels with performance advantages (increased density and volumetric net heat of combustion) over conventional petroleum-based fuels.