Orbital cysts in anophthalmic socket are infrequent. Most of the cysts reported are anterior and the inability to retain a formerly well-fitted prosthesis is the most common symptom. We present a posterior conjunctival cyst developed after a dermo-fat graft reconstruction in an eviscerated socket. Eleven years after evisceration surgery due to irreparable ocular trauma an extrusion of the orbital implant occurred. Removal of the orbital implant and a socket reconstruction with dermis fat graft was done. Three years later, the patient again returned back to the treating ophthalmologist with complaint of an inability to retain the formerly well-fitted artificial prosthesis. A detailed ophthalmic examination failed to reveal any abnormality. The CT scan showed a posteriorly located conjunctival cyst in the right orbit. Tricholoroacetic acid (TCA) was injected intracystically into the conjunctival cyst. Ten months of follow-up did not show any recurrence of the conjunctival cyst and allowed complete tolerance of the prosthesis. This case report highlights the role of tricholoacetic acid in treating a posteriorly located conjunctival cyst in an anophthalmic socket.