The effects of crossed electric and magnetic fields on the electronic and exciton properties in semiconductor heterostructures have been investigated within the effective-mass and parabolic band approximations for both bulk GaAs and GaAs-Ga1-xAl xAs quantum wells. The combined effects on the heterostructure properties of the applied crossed electric/magnetic fields together with the direct coupling between the exciton center of mass and internal exciton motions may be dealt with via a simple parameter representing the distance between the electron and hole magnetic parabolas. Calculations lead to the expected behavior for the exciton dispersion in a wide range of the crossed electric/magnetic fields, and present theoretical results are found in good agreement with available experimental measurements.10381041Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)