The antimicrobial activity of substances present in the egg wax of Amblyomma cajennense (Fabricius) was studied, focusing on bacteria, fungi and yeast. Wax was extracted using chloroform/methanol (2:1), and antimicrobial activity was evaluated by the solid culture diffusion assay method, with evaluations at 24, 48 and 72 hours after inoculation. The best results were obtained against yeasts, fungi and Gram-positive bacteria. For enteroviruses, no cytophatic effect in Vero cell cultures was observed for at least 48 hours, and the cell morphology was preserved, suggesting a very interesting potential virustatic activity.