Heat treatment at 35 C for 56 days or at 36 C for 39 days completely eliminated leafroll virus from tubers of several potato varieties. Tuber size had little effect on ability to survive the treatment or on the time required for the elimination of leafroll. Tuber losses after heat treatment range from slight to as high as 50%. Heat treatment materially delayed development of sprouts and consequent plant emergence. It appeared to have little effect on either virus X or spindle-tuber virus. An equation and graph are presented to show the relationship of time and temperature to the elimination of leafroll virus in these experiments and some conducted by others. Heat treatment has proven of value in the elimination of leafroll virus from small lots of seed of special value in a breeding program.