We report perpendicular transport measurement on a series of GaAs-AlAs superlattices in the presence of applied hydrostatic pressure up to 11Kbar. The calculation of the minibands widths and their relative position was performed taking into account a K.P model, which allowed the determination of the direct or indirect characteristic for each sample. Considering the relative fast rate in energy (approximately 12meV/Kbar) of the Γ miniband relatively to the X states we interpreted the pressure effects with a good qualitative agreement.