This study was undertaken to expand the current knowledge of the morphology and morphometry of rostellar hooks of protoscoleces from the metacestode E. granulosus. Protoscoleces were isolated from livers and lungs of naturally infected ovines and bovines obtained from abattoirs in Peruvian provinces (Arequipa, Cuzco, Puno, Huancavelica and Junin). Brightfield microscopy, confocal laser scanning microscopy, differential interference contrast and variable pressure scanning electron microscopy were used. Morphometry was made using computer image analysis. The application of these assay indicated that the large hooks frequently had thin guards and an irregular surface between the guard and handle. Data also showed that the small hooks presented rounded and stout guards. The blade did not show any relevant feature. No clear morphological distinction was observed between large and small hooks....