Purpose: To report a case of pterygium surgery with conjunctival autograft followed by focal necrotizing scleritis due to foreign body entrapment in the scleral bed. Case Report/Results: This is a case report of a 76-years-old male patient who underwent nasal pterygium surgery and developed focal necrotizing scleritis secondary to foreign body entrapment under conjunctival autograft. One month following surgery, slit-lamp examination demonstrated a progressive thinning of the surgical area with focal inflammatory signs. A small synthetic fiber was identified to be trapped under the graft. A second intervention was performed with foreign body removal and a new conjunctival graft. Despite the surgery, focal scleral melting continued to progress and the patient was placed under systemic corticotherapy and submitted to amniotic membrane graft with epithelial side up. During the follow-up period there was a good tissue response. Conclusion: Despite being a safe and quick procedure, pterygium surgery can sometimes elicit new challenges.