Background <p>Black hairy tongue, also known as lingua villosa nigra, is a reversible benign disease on the dorsum of the tongue characterized by elongated and hypertrophied filiform lingual papillae. Necrotizing sialometaplasia; on the other hand, is a benign reactive inflammatory disorder involving a minor salivary gland. The pathophysiology driving black hairy tongue and necrotizing sialometaplasia remains unclear; however, common predisposing factors for both conditions include smoking, alcohol, and drugs, and in this case, paroxetine, a selective serotonin reuptake inhibitor.</p> Case presentation <p>A 27-year-old Caucasian (British) lady presented with a 4-month history of recurrent ulcerations on her soft palate a few months after she was commenced on paroxetine for her mental health. The lesions were managed conservatively. Following a quiescent period of 19&#xa0;months, she presented with a very inflamed and ulcerated palate, with heavy deposits of debris on a brown hairy tongue. Her mental health did not improve with paroxetine; hence, paroxetine was stopped and she was started on a different class of antidepressants. Both of her oral lesions markedly improved following the withdrawal of paroxetine.</p> Conclusion <p>This case demonstrates the need to consider black hairy tongue and necrotizing sialometaplasia as differential diagnoses in patients with relevant risk factors presenting with oral lesions. Black hairy tongue and necrotizing sialometaplasia can both be managed conservatively by removal of the causative factor and maintaining good oral hygiene; nevertheless, timely and accurate diagnosis is important owing to the fact that necrotizing sialometaplasia may closely resemble more sinister pathology. Clinicians may also consider including black hairy tongue and necrotizing sialometaplasia as rare side effects of paroxetine when offering medication counseling.</p>