We report a rare case of malignant schwannoma of the brachial plexus treated during a surgical campaign aimed at the poorest communities in the Cuzco region of Peru.A Peruvian 40-year-old-female from a mountain community presented with a mass on the lateral side of her left supraclavicular space.No imaging tools were available during this surgical campaign and so a biopsy of the tumor was carried out.Histopathological examination revealed it to be a low grade malignant schwannoma.A nerve enucleation of the tumor was chosen as neither chemotherapy nor radiotherapy was available.The tumour was a firm mass 4 cm x 3 cm x 2 cm in size.After excision of the lesion the patient presented neurological sequelae(deltoid,bicep,and tricep weakness)but her condition improved over the next 3 years.We report this case of malignant schwannoma of the brachial plexus as its incidence is very rare(the reported incidence is 0.001%)and because of its challenging treatment in poor healthcare conditions.