The rate of flame spread across the surface of liquid fuels (mainly n-decane, but also n-nonane, n-undecane, dipentene, kerosene, and n-butanol) has been examined in detail for a wide range of laboratory variables. Many hundreds of carefully controlled tests have been performed aimed at elucidating the dependence of the flame spreading velocity on (1) the purity of the fuel, (2) the mode of ignition, (3) the temperature of the fuel. (4) the dimensions and material of the fuel container, and (5) the depth of the fuel layer. The effects of environmental parameters (atmospheric pressure, air temperature and relative humidity) have also been investigated, but non-systematically. The results show that the flame spreading velocity is susceptible to changes in most of these parameters. This work constitutes the first systematic variation of all the laboratory variables with the view to obtaining flame spreading data which are meaningfully applicable to any apparatus and also to ‘real’ liquid fuel fires.