GaAs/GaAs1-xPx strained multiple quantum well (SMQW) structures with x ranging from 0 to 0.5 were prepared by gas‐source molecular beam epitaxy. High‐resolution x‐ray rocking curves and transmission electron microscopy show the multilayered GaAs/GaAsP structures to possess good periodicity and crystalline quality. Photoluminescence and photoluminescence excitation spectra show sharp and distinct peaks that are attributed to the various interband excitonic transitions in quantum wells. An energy‐level calculation based on an envelope function model suggests Qv=ΔEv/ΔEg=0.42 for strained GaAs/GaAs0.61P0.39 quantum well structure. Moreover, a 90‐meV valence‐band offset for a GaAs(76.5 Å)/GaAs0.68P0.32(76 Å) SMQW structure is determined from photoluminescence measurements under hydrostatic pressures.