Levamisole-induced vasculitis is a well-characterised antineutrophil cytoplasm antibodies (ANCA)-positive vasculitis in cocaine abuser patients. However, due to the short half-life of levamisole in serum and urine, the causal role of levamisole is not established. Here we report the detection of both levamisole and cocaine in hair samples of a patient who presented with an ANCA-positive vasculitis. The higher concentration of levamisole in proximal sample of the hair confirms that the patient abused of cocaine added with levamisole in the days preceding the development of skin lesions. Although a direct causative role has not been established, our report strongly suggests that levamisole may have triggered vasculitis in this case.