Flavescence doree' (FD) associated phytoplasmas are molecularly distinguished in strains belonging to 16SrV-C and -D sub- groups that are geographically separated in the majority of the European countries where the disease was reported. While the sub- group differentiation on the 16S ribosomal gene is quite stable, RFLP analyses on the translocase gene allow differentiation of subtypes in both subgroups confirming ability of FD phytoplasmas to rapidly differentiate lineages with possibly diverse aggres- siveness.