We describe a case of chronic conjunctivitis related to phthiriasis palpebrarum. A 36 year-old female presented with gradual pruritus and painless ocular hyperaemia over the previous 3 months. On examination, nasal pterygium, conjunctival hyperaemia, oedema, and mild hypertrophy of the palpebral margin were observed. A slit-lamp examination revealed numerous creamy oval structures approximately 1 mm in diameter localised in the middle area of the lashes, and bloody crusts and a semi-transparent deposit were present in the superior palpebral margin. Based on the observation of numerous nits at the base of the eyelashes and the ectoparasite in the palpebral margin, a diagnosis of phthiriasis palpebrarum was made. The patient was referred to an infectologist for evaluation of other sexually transmitted diseases and examination of other body areas. She was successfully treated with oral ivermectin, shampoo for ciliary hygiene and artificial tears. Other recommendations to avoid re-infestation were made, such as changing, washing and sterilising clothes, towels and sheets daily. This report emphasizes the importance of the correct diagnosis and management of this disease, considered as sexually transmitted.