The production losses associated with European stone fruit yellows (ESFY, 16SrX-B) phytoplasmas in Italian plum orchards reach up to 40% in Japanese plum. During six years a trial was carried out in Vignola area (Northern Italy) to assess the susceptibility of several plum varieties to the infection by ESFY phytoplasmas. In the surrounding of the experimental orchard ESFY presence was identified in declining cherry; Cacopsylla pruni was negative to phytoplasma presence, while Fieberiella florii specimens resulted infected by 16SrX-B phytoplasmas (Landi et al., Bulletin of Insectology, 60, 163-164. 2007), providing evidence for the pathogen presence in the environment. Varieties, cultivars and new selections of European and Japanese plum employed were grafted on Myrabolan 29C, and derived from commercial nurseries and from breeding programs. Plants were evaluated in 2-4 plots of four plants each. Yearly monitoring by visual inspection and PCR/RFLP identification of phytoplasmas allowed verifying the ESFY phytoplasma presence in the orchard since the first year of plantation. After a scattered phytoplasma presence detected in the year of plantation mainly in asymptomatic plants, an increasing ESFY presence in both symptomatic and asymptomatic plums was observed in subsequent years. After the six years monitoring among the 30 Japanese plums eight selections showed ESFY symptoms or pathogen presence in the 50% of plants, and nine selections showed 20% of infection. Only nine among cultivars and selections -Bragialla, Brarossa, Fortune, Ruby Crunch, n. 89.030.020, n. 89.030.031, n. 89.036.131, n. IFF/260, and n. IFF271- showed absence of both symptoms and pathogen. Although the majority of the 35 European types of plum was not symptomatic, some of the genotypes -Rheingold, Valcean, Valerie, n. 3018– showed one to three symptomatic plants ESFY-infected each, and one asymptomatic selection, n. 1474, was also positive to the sane phytoplasma in one plant.