<h3>Background</h3> Plasma cell cheilitis (PCC) is an uncommon idiopathic condition that usually affects the lower lip as circumscribed, slightly raised eroded plaques or patches, occasionally showing bleeding and crusted areas. <h3>Objective</h3> To present 2 cases of PCC affecting the lower lip of adults. <h3>Case Report</h3> An 86-year-old woman was referred with a main complaint of a burning sensation in her lower lip, particularly during ingestion of spicy food. Her medical history revealed high cholesterol and hypothyroidism while an ill-defined white plaque of unknown duration was observed in the semi-mucosa of the lower lip. The second patient was a 58-year-old man presenting a well-defined erythematous ulcer with whitish smooth margins affecting almost the entire vermilion of the lower lip. <h3>Results</h3> Both cases were submitted to incisional biopsies under diagnostic hypothesis of actinic cheilitis. Microscopic analyses revealed hyperplastic and parakeratinized stratified squamous epithelium with dense infiltrate of plasma cells in the lamina propria. <h3>Conclusions</h3> The final diagnosis was PCC. Patients were treated with topical corticoid and laser therapy with regression of signs and symptoms. PCC should be considered when evaluating cheilitis, particularly those with plasma cell infiltration.