This paper concerns the potential uses of infrared scanning for remote sensing of big game animals. The basic mechanics of the equipment are described and the method of aerial scanning explained. An operational trial of the method was performed on the George Reserve white-tailed deer (Odocoileus virginianus) herd. In addition to the regular deer population, three deer were placed in small pens under different cover conditions-open grassland, hardwoods (with the leaves down), and pine coniferous canopy. Radiometer readings on the penned deer and their backgrounds showed approximately 7 C differential in apparent temperature. The two deer in the grassland and oak woodland were easily detected, but the deer under the conifer canopy would have been missed if its location had not been known. The infrared count of the Reserve herd was 98 as compared to a population estimated by other methods at 101 head. Under the right conditions, infrared scanning will probably give better counts over large areas than any other technique available at present. However, the inability of infrared to penetrate green leaf canopy, variability of animal and background apparent temperatures depending upon weather and other factors, difficulty in distinguishing between species of animals, and high initial cost of the scanning device are substantial limitations to the use of the technique.