To study the differentiating cytomorphological features of Hodgkin lymphoma (HL) and anaplastic large cell lymphoma (ALCL) using fine needle aspiration cytology (FNAC), cytomorphological features of 16 patients with HL (n=8) or ALCL (n=8) were analyzed. In the initial cytological diagnosis prior to biopsy, HLs were properly diagnosed in 4 out of 8 cases (4 HL, 2 atypical, 2 benign), whereas all ALCL were diagnosed as malignancies. However, correct diagnosis of non-Hodgkin lymphoma (NHL) was made in only two ALCL patients (2 NHL, 1 HL, 1 sarcoma, 4 malignancy without specific type). Overall, the percentage of large abnormal cells ranged from 30% to 90% in ALCL except for one case, whereas it was less than 5% in all 8 HL. A spectrum of atypical cells was more characteristic of ALCL. In contrast, HL showed an sharp difference between reactive lymphoid cells and neoplastic ones (bimorphic pattern). Moreover, the emergence of kidney-shaped abnormal cells or wreath-like multinucleated cells was helpful in diagnosing ALCL. The combination of thesefeatures would be useful in differentiating HL and ALCL. Nevertheless, these two types of lymphomas cannot be definitely distinguished based on cytomorphological features alone. Therefore, the aim of FNAC would be to suggest a specific diagnosis and indicate the need for a biopsy.