We show numerically that correlation length at the critical point in the five-dimensional Ising model varies with system size
L as
L5∕4, rather than proportional to
L, as in standard finite-size scaling (FSS) theory. Our results confirm a hypothesis that FSS expressions in dimension
d greater than the upper critical dimension of 4 should have
L replaced by
Ld∕4 for cubic samples with periodic boundary conditions. We also investigate numerically the logarithmic corrections to FSS in
d=4.