Pseudolymphomas or B-cell lymphoma at the vaccination site have been reported by several authors. However, onset of cutaneous T-cell lymphoma with cytotoxic features is a rare complication of vaccination. We report a 27-year-old man who developed a nodule and ulcer that arose at the site of injection of influenza vaccine. The neoplastic cells reacted positively for CD56, CD3, CD2, perforin, and granzyme B, but negatively for CD4, CD8, CD10, CD19, CD30, CD34, CD79, and betaF1. Molecular studies showed T-cell receptor γ (TCR-γ) chain monoclonal rearrangement. A diagnosis of peripheral T-cell lymphoma, not otherwise specified (NOS) was established. The patient had high fever, progressive liver dysfunction and a rapid fatal evolution.