In this paper, we study the following biharmonic elliptic problem involving slightly subcritical non-power nonlinearity [Formula: see text] where [Formula: see text] is a bounded smooth domain, [Formula: see text], [Formula: see text], [Formula: see text] is a small parameter. By Lyapunov–Schmidt procedure, under suitable assumptions on the Robin function related to [Formula: see text], we construct the multi-peak solutions which blow-up and concentrate in different points of [Formula: see text] as [Formula: see text] goes to [Formula: see text].