The alignment of clusters of galaxies with their nearest neighbours and between clus- ters within a supercluster is investigated using simulations of 512 3 dark matter par- ticles forCDM andCDM cosmological models. Strongly significant alignments are found for separations of up to 15h 1 Mpc in both cosmologies, but for theCDM model the alignments extend up to separations of 30h 1 Mpc. The effect is strongest for nearest neighbours, but is not significant enough to be useful as an observational discriminant between cosmologies. As a check of whether this difference in alignments is present in other cosmologies, smaller simulations with 256 3 particles are investi- gated for 4 different cosmological models. Because of poor number statistics, only the standard CDM model shows indications of having different alignments from the other models.