There is no consensus on the choice of systemic and ophthalmic treatment for patients who develop ocular toxicity with erlotinib in the few cases reported previously. Various ocular complications related to erlotinib have been reported, with one of the most serious being corneal perforation. Our patient was at risk of potential corneal perforation because of severe cicatricial ectropion and diffuse punctate corneal epitheliopathy. Therefore, erlotinib treatment was temporarily discontinued with the approval of the oncology department and the patient was closely followed. She was prescribed steroid eye ointment, single-use preservative-free artificial tears, and eye lubricant gel to protect the ocular surface. On day 4 of treatment, the patient’s findings were significantly improved. After 1 week, the cicatricial ectropion had dramatically improved and the patient’s complaints were completely resolved. To our knowledge, there is no case report of a patient with both ocular toxicity after long-term use that shows dramatic improvement with drug cessation, and severe cicatricial ectropion affecting the entire lower eyelid. Here, we described a patient who used erlotinib for 3 years due to non-small cell lung cancer and developed severe cicatricial ectropion which improved dramatically within one week of temporarily discontinuing erlotinib and discussed the possible reasons. Although ocular complications with erlotinib are usually encountered early in treatment, it should be kept in mind that erlotinib-related ocular complications may also arise with long-term use.