In recent years, many new rootstocks obtained from interspecific crosses, roughly recognised as peach x almond or plum clones, have been introduced in Europe and little information on their resistance to soil sickness or replant problems has been available until now. A trial was carried out in the Pisa province to assess the behaviour of 9 different rootstocks planted one year after the uprooting of a 15-year-old peach orchard (cv. 'Stark Red Gold') grafted onto peach seedlings. Twenty-five one-year-old maiden trees of cv. 'Flavorcrest' (grafted onto GF 677, Cadaman-Avimag, Barrier 1, Sirio, Mr.S.2/5, Ishtara-Ferciana, Julior-Ferdor, Adesoto and Penta) were planted for each rootstock, in the same position as the previous rows, in January 1998 at 4.5 x 2.0 m spacing and trained to the free spindle ('fusetto') system: Measurements of the vegetative activity, yield and phenology of each tree were recorded yearly. Preliminary results showed that the mortality rate was poor in each of the rootstocks tested but induced vigour appeared to be strongly affected by rootstock and replant soil. GF 677 was the most vigorous rootstock, followed by Barrier 1 and Cadaman clones; all of the plum clones induced less vigour than peach x almond clones; Sirio showed the lowest vigour (60% less than GF 677) and a very high variability in tree size. The yield in the third year (2001) was highest in Cadaman, GF 677 and Barrier I clones (15.9, 14.3 and 11.3 kg/tree, respectively), which also gave a good fruit size (> 160 g). Among the plum hybrid clones, Ishtara and Adesoto appeared very interesting because of their good productivity and fruit size, even if to a lesser extent than the peach x almond hybrids. Julior and Sirio showed the poorest fruit size (149 and 137 g, respectively) and yield per tree.