The results of a series of measurements into the electrical energy savings achieved by PIR and photocell control of individual fluorescent luminaires are presented. Two versions of the PIR/photocell control system (referred to as ＇intelligent＇ luminaires from here on) were tested. The results are compared with estimates of the performance of switchstart and ＇standard＇ high frequency fluorescent luminaires. The results show that the original ＇intelligent＇ control system installed achieved electrical savings of around 10% when compared to ＇standard＇ high frequency fittings. An improved version of the ＇intelligent＇ system achieved energy savings averaging around 80% when compared to ＇standard＇ high frequency fittings. This latter result is in line with the savings predicted by BRE Digest 272((1)) for photoelectric dimming control. The study also showed that these fittings need proper commissioning to return their full potential savings.