The applicability of intermediate-energy heavy-ion charge-exchange reactions for measuring Gamow-Teller strength in nuclei is studied. A strong absorption model for such reactions is developed. Within the framework of this model, we define a sensitivity function which determines the important region of the target transition density in momentum space. It is found that the {ital L}=0 cross section provides a relatively model-independent measure of Gamow-Teller strength. An understanding of the large {ital L}=2 cross sections observed in heavy-ion-induced reactions is achieved. Specific application is made to the ({sup 12}C, {sup 12}B) reaction at {ital E}/{ital A}=70 MeV.