En México la giardiosis es la protozoosis intestinal más frecuente en los niños, para el tratamiento se utilizan los nitrofuranos, nitroimidazoles y benzimidazoles. Recientemente se introdujo un antiparasitario polivalente: la nitazoxanida (Ntz); del cual hay pocos estudios sobre su actividad antigiardiásica.In Mexico giardiosis is the most prevalent parasitic disease in children. Treatment with antiparasitics derived from: nitroimidazoles, benzimidazoles and nitrofuranes have been used; but, some of them have undesirable side effects. Recently nitazoxanide (Ntz) was introduced in Mexico; however, there are few studies on Giardia duodenalis susceptibility to Ntz.