Subtotal pars plana vitrectomy was performed in four patients with chronic toxocaral endophthalmitis. In two instances, chronic intraocular inflammation proved unresponsive to intensive corticosteroid therapy, but improved dramatically following vitrectomy. In one patient, a dense retrolenticular membrane was removed, and intractable amblyopia was prevented. Vitrectomy relieved vitreoretinal traction involving the macula in two instances and cured a peripheral traction retinal detachment in a third. Information gleaned from these cases suggests new guidelines for the laboratory confirmation of ocular toxocariasis. Patients with toxocaral endophthalmitis may benefit from pars plana vitrectomy when chronic inflammation does not respond to medical measures or when such inflammation causes permanent structural changes that threaten or interfere with central vision.