Asteroid hyalosis (AH), a condition in which calcium-lipid complexes form in the collagen mesh-work of the vitreous, affects from 0.5% to 0.9% of the general population. In patients with dense AH and visual loss, obscuration of fundus detail on opthalmoscopy and even on fluorescein angiography may complicate the diagnosis and treatment of underlying posterior segment disease. To evaluate the usefulness of vitrectomy in AH, we reviewed 7 cases of dense AH in 6 patients who underwent vitrectomy in the setting of decreased visual acuity of uncertaincause. Additional diagnoses made following surgery included age-related macular degeneration (ARMD) in 2 eyes, ARMD with associated epiretinal membrane in one eye, and the staging of diabetic retinopathy as proliferative in one eye. Although no major surgical complications occurred in this series, the potential for serious complications exists, and pars plana vitrectomy (PPV) should be considered only after less invasive diagnostic evaluations and therapeutic approaches have been exhausted. © The Ophthalmic Communications Society, Inc.