This study evaluated the efficacy of cooking hamburger patties by infra-red sources at lambda(max) of 2.7 mu m (Mid-IR) and at lambda(max) of 4.0 mu m (Far-IR). With the higher energy source, the change in core temperature follows closely the change in surface temperature, cooking time was short and was independent of the fat content of the samples. With the lower energy source, the rate of core temperature rise was dependant on the fat content of the samples and target core temperature was achieved more quickly as the fat content of the samples increased. At about 50% fat content, the cooking time for either source was the same. With the far infra-red radiation source target core temperature was achieved at a lower surface temperature, with less surface drying and charring. The gas consumption when using the longer wavelength infra-red source was reduced by 55% over that for the shorter wavelength, higher energy source.