Background: Sentinel lymph node biopsy (SLNB) is a key staging tool for cutaneous melanoma. Accurate staging is vital for prognosis and guiding adjuvant therapy. However, false-negative (FN) SLNB results remain most common in cutaneous melanoma of the head and neck.This is likely due to the complex lymphatic drainage in the head and neck. Aim: This literature review synthesizes current evidence on SLNB FN rates in head and neck melanoma and evaluates the factors contributing to diagnostic inaccuracy. Methods: PubMed database was searched using the terms “sentinel lymph node biopsy” and “head and neck melanoma”. A review of cohort studies, systematic reviews and meta-analyses was conducted, examining reported SLNB FN rates, mapping techniques, tracer modalities and surgical approaches. Results: In all studies, FN SLNB was defined as recurrence of tumour in a previously identified negative nodal basin. In Miller et al.’s cohort study, a false negative rate of 32.1% was identified amongst patients with nodal disease. In Johnston’s systematic review, a total of 27 studies demonstrated a FN rate of 21.3%. Across the literature, recurring factors were associated with FN SLNB: incomplete nodal mapping, reliance on planar LSG alone, harvesting a single node, omission of intra-parotid/deep cervical nodal basins and delays in intervention following negative SLNB. The complex and highly variable lymphatic drainage patterns contribute significantly to missed metastatic nodes. Conclusions: The literature consistently identifies higher FN rates for SLNB in head and neck melanoma, despite advances in tracers and the use of multimodal imaging. In order to improve survival outcomes and reduce time to treatment delay, continued refinement of mapping technologies and a standardized protocol (no. of LN/surveillance imaging) is imperative for reducing FN rates. References: 1. Miller et al. False-negative sentinel lymph node biopsy in head and neck melanoma. Otolaryngol Head Neck Surg. 2011; 145: 606-11.