Although the pathogenesis in most cases of intermediate uveitis is unknown, a small minority of cases is associated with a variety of specific inflammatory etiologies: sarcoidosis; multiple sclerosis; Lyme disease; syphilis; ocular lymphoma; and as a rare manifestation of Behçet's disease and AIDS. A 61-year-old woman developed pars planitis after cataract surgery. A vitrectomy was performed after ten months when a white capsular plaque and an hypopyon developed. Propionibacterium acnes was isolated. The intermediate uveitis was not controlled until later removal of the intraocular lens and capsular remnants. Chronic propionibacterial endophthalmitis may be a cause of intermediate uveitis.