Mammary internal and surface temperatures and milk temperature were correlated using five lactating goats. Internal mammary temperature was estimated using temperature-sensitive transmitters placed deep within the parenchyma of each mammary half. External mammary temperature was estimated using infrared thermography of four mammary skin sites: T1, teat end; T2, teat base; G1, about 20 mm above the teat base; and G2, about 20 mm ventral to the base of the gland deep to the thigh. The thermistor bead used for estimating milk temperature was placed in the claw piece where the short milk tube of the liner attaches. This placement minimized cooling effects of milk contact surfaces. The overall correlations of milk temperature with mammary temperatures ranged from 0.45 to 0.64. Correlations among the six paired values for the four external sites ranged from 0.76 to 0.92. Milk and surface temperatures, milking time, and milk weight were employed in various combinations as covariables; these were calculated within animal, within half. Milk temperature was the single most important predictor of internal mammary temperature in all models. Milk temperature alone or combined with covariables can be used to predict internal mammary temperature.