Infectious diseases are one of the main causes of lymph node enlargement both in children and adults and represent a benign and reversible process. Clinical evaluation, serological data, microbiological and molecular tests and imaging techniques are generally used in the diagnosis of reactive lymph nodes determined by infectious diseases but, in some cases, do not assess their origin and nature. Surgical excision and histological control represent the gold standard in the diagnosis of lymphadenopaties, but they might be unnecessary procedures just for diagnostic purposes in benign reactive lymph nodal enlargement. Fine Needle Cytology (FNC) has gained a definitive role in the diagnosis of lymphadenopaties being an accurate, rapid, minimal invasive and cost-effective procedure useful for the clinical management and therapeutic decisions. This study reports the use of FNC in the diagnosis of reactive lymph nodes in infectious diseases, exploring possibilities and limitations of the technique in this specific clinical setting.