An association between crystalline silica and immune disease has long been recognized. However, despite ongoing case reports of systemic autoimmune disease in silicone implant recipients, the available data has not been sufficient to prove or disprove a causal relationship. Silicone has been shown to "bleed" from the implants and can migrate to distant sites. There is evidence of cellular and humoral immune responses to silicone in vivo, but the role of these responses in the development of connective tissue disorders has not been determined. Further studies are necessary to elucidate the role of silicone, if any, in the pathogenesis of autoimmune connective tissue disease. Meanwhile, the implant population needs to be closely monitored; their clinical management should be based on a case by case evaluation.