Back pain and spine tenderness over the involved spine segment are common clinical findings of a number of relative benign conditions. However, back pain may be the presenting symptom of vertebral metastases in patients with systemic cancer, including hepatocellular carcinoma, a not uncommon complication in HCV-HIV infected patients. We describe a case of a 51-year-old intravenous drug user with HIV and HCV co-infection who developed dorsal spondylodiscitis due to Pseudomonas aeruginosa, which improved following antibiotic therapy. Three months after the end of therapy, the patient referred recurrence of back pain. The MRI showed different vertebral lesions of the dorsal spine and costal arch which turned out to be hepatocellular carcinoma metastasis at the histological examination. The patient had never been treated with the interferon-ribavirine combination therapy because of a major depressive syndrome. Interferon-free regimens are urgently required for HIV-HCV coinfected patients, especially when interferon-based regimens are contraindicated.