Mycelial interactions were studied between 28 isolates of Amylostereum areolatum and 15 of A. chailletii from wounded spruce in 10 sample plots in Sweden and Lithuania. Based on somatic incompatibility, nine vegetative compatibility groups (VCGs) of A. areolatum were detected. Five of these VCGs were isolated from two or more trees and included 24 (86%) of all isolates. In A. chailletii, 12 VCGs were found and three contained two isolates each. Grouping of isolates into VCGs was more pronounced in A. areolatum. Two of the A. areolatum VCGs had wide geographical distribution. VCG A2 was isolated from 14 different trees in two Swedish and four Lithuanian sample plots. VCG A1 was found in one plot in Sweden and in two in Lithuania. VCGs of A. chailletii had a local distribution and were confined to a single sample plot or to a forest stand. In A. areolatum occurrence of compatible pairings between isolates was uniform in all spatial scales of investigation: within a plot, within each country and among both countries. The proportion of somatically compatible A. chailletii isolates was significantly lower and decreased with geographic distance.