We study flavour issues in nonsupersymmetric intersecting brane models.
Specifically, the purpose of the present paper is twofold: (i) to determine
whether realistic flavour structures can be obtained in these models, and (ii)
to establish whether the non-supersymmetric models address the gauge hierarchy
problem. To this end, we find that realistic flavour structures, although
absent at tree level, can arise even in the simplest models after effects of 4
fermion instanton--induced operators and radiative corrections have been taken
into account. On the other hand, our analysis of flavour changing neutral
currents (FCNC), electric dipole moments (EDM), supernova SN1987A and other
constraints shows that the string scale has to be rather high, 10^4 TeV. This
implies that non-supersymmetric intersecting brane models face a severe
finetuning problem. Finally, we comment on how non--trivial flavour structures
can arise in supersymmetric models.Comment: 33 pages, 11 figures, matches the NPB versio