A HIV-positive patient, 3 months after the treatment initiation with lopinavir-/ritonavir (LPV/r) acquired macroglossia. The tongue biopsy revealed mature adipose tissue accumulated into submucosa. The drug was discontinued and the patient showed a significant improvement. This case is the first case in the medical literature of acquired macroglossia because of LPV/r, a drug causing changes in body fat composition.