Evidence suggests that coevolution of a suite of ecological, behavioral, morphological, and physiological traits has accompanied the elaboration of niches of Caribbean Anolis lizards. Yet, information is lacking as to the extent to which energy expenditure is coadapted with the thermal or structural niche. I tested the prediction that body mass and standard metabolic rate (SMR) would covary with the thermal or structural niche of Anolis lizards. An analysis of standardized independent contrasts indicated that lizards occupying cooler thermal niches (at higher elevations) had relatively low mass-independent energy costs. Mass-independent SMR at 30°C was significantly related to the species' thermal niche (r = 0.88, P = 0.02). Other associations with structural niche and body mass were suggested. Possible causes of shifts in energy expenditure with changes in niche are discussed.