Electromigration was investigated in 1×4×250 &mgr;m aluminum conductors which were recrystallized to produce chains of single‐crystal grains, ’’bamboo’’ structures. Median lifetimes were substantially longer than are found in normal polycrystalline Al, reflecting the lack of grain boundary diffusion paths. However, mass fluxes estimated from damage features were larger and more variable than is consistent with a normal lattice diffusion mechanism. An enhanced lattice diffusion mechanism is proposed to account for these observations.