Energy utilization of natural prey items by Mississippi bobcats (Felis rufus) was measured and annual prey requirements were estimated. Male and female bobcats were fed 5 diets of natural prey items, December 1990-February 1991. There were significant differences in amount of energy (kcal) in prey items, with white-tailed deer (Odocoileus virginianus) meat (5.7295) greater (P < 0.05) than fox squirrel (Sciurus niger) (5.0304). The deer diet also was significantly greater (P < 0.05) than the rodent diet and the rabbit and rodent diets in metabolizable energy (ME) and metabolizable energy content (kcal ME/g DM), respectively. Digestion coefficients for dry matter differed between diet types with the deer diet (81.3%) significantly greater (P < 0.05) than the rodent (63.68%) and rabbit (63.88%) diets. There were no significant differences (P > 0.05) between male and female bobcats in digestion efficiency of dry matter or energy (kcal). Energy values obtained in this study were used to determine the minimal mean number of prey species an average bobcat would require annually to survive. Based on proportions of prey found in current food habits studies, a female bobcat (8.17 kg) would require 94 rabbits, 101 squirrels, 226 cotton rats, 576 whitefooted mice, and 0.7 white-tailed deer while a male bobcat (9.09 kg) would require 102 rabbits, 110 squirrels, 245 cotton rats, 624 white-footed mice, and 0.76 white-tailed deer annually to survive.