The combustion/pyrolysis of three chemically different hydrocarbons, toluene, n-heptane, and propanol-1, has been investigated in reflected shock waves. The formation of soot and polycyclic aromatic hydrocarbons (PAHs) has been studied, and the factors which influence the production of these compounds during liquid spray combustion have also been investigated at temperatures between 1000 and 3000 K and pressures of 2-25 bar. The results indicate that formation of soot and PAH is significantly dependent on the chemical properties of fuel, temperature, and oxygen concentration, but the pressure dependence is found to be minimal in the pressure range less than 25 bar. The results are instrumental in adding to our understanding of the soot and PAH formation chemistry.