Abstract Photoluminescence excitation (PLE) spectroscopy has been used to characterise miniband formation in (InGa)-AsGaAs superlattices with nominally 50 Å wide wells and barriers between 200 Å and 50 Å. The nominal composition of the alloy layers was ∼ 0.06. The observed exciton features are consistent with theoreical predictions of both parity allowed and forbidden transitions, at the mini-Brillouin zone centre and edge, including transitions associated with M 1 critical points in the superlattice bandstructure. Furthermore, as the GaAs thickness is varied we monitor changes in shape of the PLE spectra in the region of the first free electron to heavy-hole subband continuum, brought about by the electron-hole Coulomb interaction within the miniband. We also report PLE measurements on a structure which has been designed specifically to maximise the possibility of revealing a Δn = 0 exciton resonance below the saddle point.