BACKGROUND: Cyclitic retrolental membranes (CRM) in children are usually associated with chronic uveitis or genetic syndromes. We report two rare cases of idiopathic CRM. PATIENTS AND METHODS: Two girls aged 9 and 13 years with visual acuities (VA) of 0.05 underwent lensectomy and anterior vitrectomy with dissection of the central part of the retrolental membrane and intraocular lens (IOL) implantation. RESULTS: The clinical evolution was excellent for the 9 year old girl who recovered 1.0 VA after 2 months. Histological examination revealed a fibroelastic tissue of unknown origin without inflammatory components. The 13 year old girl showed VA of 0.6 within 1 month. However, a recurrent CRM developed with retinal detachment and proliferative vitreoretinopathy (PVR). Vitrectomy, complete excision of the CRM and 360 degrees retinotomy with silicon oil tamponade attached the retina with limited visual recovery. Histology showed fibrovascular tissue with inflammatory components infiltrating the CRM. CONCLUSIONS: Idiopathic CRM in children are rare and can be composed of different histological tissues with very different clinical outcomes.