We present a case of mandibular involvement with Langerhans cell histiocytosis (LCH), diagnosed by ultrasound-guided aspiration and subsequently confirmed by incisional biopsy and immunohistochemistry in an eight-year-old boy. The cytologic findings included the presence of characteristic Langerhans cells of both mononucleate and multinucleate form. Diagnostic confirmation was obtained by immunopositivity for S-100 protein and CD1a of Langerhans histiocytes on paraffin-embedded sections obtained during incisional biopsy of the right mandibular area. By reporting a case of childhood LCH, we correlate the cytologic findings with histologic features and discuss the role of aspiration cytologic diagnosis in such a rare and cytomorphologically characteristic case.