An evaluation is made of thermal stresses in rolls, resulting from the temperature gradient within the body of a hot strip mill. It was found that roll spalling and failure are caused by axial stresses, that are otherwise neglected in many analyses. An analysis of the behavior of thermal stresses in rolls during hot flat rolling has been undertaken, based on experimental temperature measurements, and considering a variation of temperature in the longitudinal direction of the roll. The thermal stress distribution in the middle cross section of the roll under the strip was presented. The effect of temperature decay beyond the strip edge and the widening-out of bars during the rolling schedule were studied.