A 27-year-old British woman experienced recurrent ulcerations in her soft palate after starting paroxetine, an antidepressant. She developed a brown hairy tongue and significant oral lesions. These conditions, known as black hairy tongue and necrotizing sialometaplasia, are benign but can appear similar to more serious diseases. Factors like smoking, alcohol, and certain medications, including paroxetine, may contribute to these conditions. After 19 months, her oral health worsened, prompting a change in her treatment plan. Upon discontinuing paroxetine and switching to a different class of antidepressants, her lesions improved significantly. This case highlights the importance of considering both conditions as possible diagnoses in patients with relevant risk factors and oral lesions. It also suggests that healthcare providers should inform patients about these potential rare side effects when prescribing paroxetine. Effective management includes removing the causative factor and maintaining good oral hygiene.