Studies on the urban heat island effects in two adjacent tropical cities, Singapore and Kuala Lumpur, are surveyed. Past efforts have concentrated on surface temperature mapping relying largely on spot measurements, which, although are inadequate, do indicate the existence of warm spots associated with urbanization. Examination of station records have indicated perceptible temperature increases in both cities, though there has been no concerted effort to facilitate comparative studies. Recent work includes implementation of more systematic data acquisition, the use of the remote technology, as well as surface energy balance modelling. Directions for future work is discussed.