Post-vaccination granulomas a well-known reaction due to aluminium adsorbed vaccines. We report three cases of children who developed subcutaneous nodules at the site of a previous injection of Tetracoq*vaccine (tetanus, diphtheria, Bordetella pertussis, poliovirus). Histologically, the lesions were characterized by a necrotizing granulomatous reaction with eosinophilic crystalline material. This material stained positively with the solochrome cyanine stain and was pink-purple. This aluminium stain enabled diagnosis of post-immunization injection-site reaction due to aluminium.