The effects of hydrostatic pressure on the Coulomb-bound states in GaAs-Ga1-xAlxAs and GaAs-AlAs semiconductor superlattices are theoretically studied. Calculations of the impurity binding energies for different configurations of the system and for various values of the hydrostatic pressure are performed in the framework of the parabolic-band and effective-mass schemes, and within the variational procedure. The hydrostatic-pressure dependence on the exciton energy is also obtained, and theoretical results are compared and found in good agreement with available experimental measurements. (C) 2008 Elsevier Ltd. All rights reserved.446809813Colombian COLCIENCIASCODI-Universidad de Antioquia AgenciesExcellence Center for Novel Materials/COLCIENCIAS [Ndegree 043-2005]Excellence Center for Novel Materials/COLCIENCIAS [Ndegree 043-2005]