This paper presents an application of artificial neural network for determination of ready reserve power required under generator outage and increased load conditions in a power system. Gas turbines or hydro plants are used as rapid reserve units. A single-layer ANN known as functional link network has been utilized for RR power determination. Training and test instances have been generated using a stochastic deterministic technique [IEEE Trans. Power Syst. 13 (1998) 649]. RRs have been obtained for a standard IEEE test system and compared with those obtained by other existing methods.