The sweet cherry (Prunus avium) cultivar 'Summit' still fits the standard of excellence for its typical characteristics, including large fruit size and cordate shape. This study was undertaken in Vila Real, northern Portugal, with 'Summit' scions raised in a nursery on five rootstocks. The orchard trials were set up in 1999, and tree growth, yield, and fruit size were monitored up to the 6th leaf. At this phase, the rootstock trunk cross-sectional areas (TCSAs) for Maxma 14, Cab 11E, Edabriz, and Gisela 5 were 79.7%, 60.2%, 37.9%, and 29.3% of that of Mazzard, respectively. Cumulative yield was higher on Gisela 5, but it did not differ significantly from Cab 11E Maxma 14, Edabriz, and P. avium attained only 56%, 50%, and 36% of H05125;