Protein glycosylation is a widely distributed posttranslational modification, though not exclusive to eukaryotic cells. The addition of glycans to proteins plays crucial roles in protein folding and secretion, cell-cell interaction, functional specificity and structural properties of both secreted and membrane-bound proteins. In this review, we emphasize the N-linked glycosylation pathway found in eukaryotic cells, the contribution of processing α-glycosidases, and the use of such enzymes as potential drug targets to control some medically relevant viral infections. Thus far, some inhibitors of the endoplasmic reticulum α -glucosidases such as castanospermine, 1-deoxyjirimycin and derivative molecules have been shown to control viral particles in both in vitro and in vivo models. Nonetheless, the mechanism used for these molecules to inhibit specific viral groups, without affecting the host cells, remains unknown. Furthermore, certain α-mannosidase inhibitors have proven to be helpful in cancer therapy, either improving the sensitivity to chemotherapeutic drugs or reducing metastasis of the tumor. Undeniably promising, the use of α-glycosidase inhibitors rises as an alternative to control both viral infections and cancer. Despite the significant progress in the field, it remains to be demonstrated whether those inhibitors are good candidates to control other pathogens and if so, a careful treatment of the data must be done before extrapolating their use to other systems.