Mebendazole (MBZ) is an anthelmintic medicine known to exhibit the polymorphs A, B and C, where polymorph C is the one indicated for tablets. Mebendazole commercial tablets (references, generics and similars) were analyzed in this work using X-ray powder diffraction data and the Rietveld method (RM) aiming at characterizing and quantifying crystal phases. Form C was found in mixture with form A in formulations of 500 mg (reference and generic). One of the generics presented a batch with form B and another one with form C. All the other tablets presented form A.