Factors affecting the development of excised potato buds into rooted plants were investigated during a program to eradicate latent viruses from commercial potato varieties. Buds 0.4 to 0.8 mm long were excised from heat-treated plants and placed on media modified from that of Murashige and Skoog. Factors that influenced survival and rooting were the composition and pH of the culture medium, the season of the year, the variety of potato, and transfer of buds to fresh media during culture. Liquid medium was superior to solid, both for rate of growth and proportion of rooted buds. Common growth-promoting substances incorporated into the medium were more detrimental than beneficial. Development was optimal at pH 5.7 but rooting was inhibited at pH 4.8 or pH 6.2. Buds excised in the spring and early summer rooted more readily than those taken later in the year. Buds of most varieties rooted satisfactorily but we failed to develop a medium that would guarantee a large proportion of rooted plantlets from excised buds of any variety at any time of the year. Even with the best medium tested, usually less than half of the excised buds developed into established plantlets without transfer to fresh medium. Plantlets that developed shoots without roots were sometimes established by transferring them to soil.