Catalytic steam reforming of ethanol over a Ru/Al2O3 catalyst in the temperature range 873-973 K was studied. The influence of inlet ethanol concentration on ethanol conversion and hydrogen yield was investigated. The conversion vs space time data was subjected to the integral method of analysis. The results show that the reaction order with respect to ethanol is 1. An activation energy of 96 kJ mol(-1) was obtained. A possible reaction sequence for ethanol steam reforming was suggested. A rate expression was derived assuming that the decomposition of an activated complex formed during reaction into intermediate products was the rate-determining step.