Considerable interest and efforts are directed at determining the extent to which silicone gel breast implants may contribute to the risk of developing autoimmune disease. There is also comparable interest in determining the extent to which silicone may alter the natural history of an established autoimmune disease. Recently, there has been concern over the possibility that children of women with silicone breast implants might somehow be adversely affected because of either trans-mammary or trans-placental delivery of silicone during either breast feeding or pregnancy. Herein, we describe two children of mothers with silicone breast implants, both female, aged approximately 3 and 9 years, both of whom had long-standing myalgias that were unexplained and did not fit current clinical criteria for juvenile arthritis. Both were found to have positive antinuclear antibodies. Additionally, the 9-year-old girl was found to have a significantly high titer of antibodies against denatured human type II collagen; indeed, her titer was six standard deviations above the mean for normal controls. There have been numerous previous studies which have documented an adverse impact of trace metals, chemicals and some medications on the morphologic and neurologic development of children exposed in utero. Much less information exists on potential toxicity experienced by a neonate through breast feeding, although examples of toxic transmission have been reported. In Western Europe, but not the United States, women with silicone breast implants are advised not to breast feed. Further research should address these concerns and, in particular, women with silicone breast implants, with evidence of leakage or rupture, should refrain from breast feeding until further data are obtained.