The energy expenditure of six goats averaging 35 (SE 0·3) kg was measured when the animals were standing or walking on a treadmill enclosed in a confinement-type respiration chamber at different speeds (0·167, 0·333 and 0·500 m/s) and slopes ( — 10, — 5, 0, +5 and +10%). The energy costs of locomotion, estimated from the coefficients of linear regressions of heat production (HP) per kg body weight v. distance travelled were 1·91, 2·33, 3·35, 4·68 and 6·44 J/kg BW per m for — 10, — 5, 0, +5 and +10% inclines respectively, indicating that the energy expenditure of walking over standing changes with slope according to a slightly curvilinear relationship. The energy cost of raising 1 kg body weight one vertical metre was found to be 31·7 J, giving an average efficiency for upslope locomotion of 30·9%. The energy recovered on vertical descent was estimated as 13·2 J/kg per m, indicating an efficiency of the energy recovered above the theoretical maximum.