Black hairy tongue (BHT) is an acquired, benign condition marked by elongation and discoloration of the filiform papillae on the dorsal tongue, producing a characteristic hair-like appearance. This review provides comprehensive insights into its pathogenesis, risk factors, clinical features, differential diagnoses, and treatment approaches. BHT is often associated with poor oral hygiene, smoking, certain medications, and systemic disorders. Diagnosis is primarily clinical, while management involves elimination of contributing factors and improved oral hygiene. Recognizing this self-limiting condition is essential to avoid unnecessary interventions and to provide appropriate reassurance and guidance to affected individuals.