Numerous meta-analyses, weight-of-the-evidence, and critical reviews have summarized data from case-control and cohort studies, published through 1999, which have been conducted to evaluate the potential association between cosmetic silicone breast implants and the occurrence of well-defined connective tissue diseases, as well as a hypothesized new atypical disease, which does not fulfill established diagnostic criteria for any known connective tissue disease. These reviews have unanimously concluded that there is no evidence of an association between breast implants and any of the traditional connective tissue diseases evaluated individually or combined or atypical connective tissue disease. We have performed an updated review of the results of epidemiologic studies published since 1999. Two long-term follow-up studies of women with breast implants in Denmark and a retrospective cohort study in Australia found no excess of definite connective tissue disease, including rheumatoid arthritis, systemic sclerosis, systemic lupus erythematosus and Sjogren's syndrome, among women with cosmetic breast implants compared with breast reduction or other plastic surgery controls or women in the general population. No consistent evidence was observed of increased risk of definite connective tissue disease in women with extracapsular ruptures in 2 studies which evaluated risk by rupture status among women with cosmetic breast implants. The results of several studies provide no evidence of a higher frequency of undefined connective tissue disease among women with cosmetic breast implants or of a rheumatic symptom profile unique to these women and/or indicative of a specific atypical connective tissue disease. In conclusion, the most recent epidemiologic investigations have been remarkably consistent with earlier epidemiologic studies in finding no evidence of an excess of any individual connective tissue disease or all connective tissue diseases combined, including both established and atypical or undefined connective tissue disease, among women with cosmetic silicone breast implants. Thus, the conclusions reached in earlier independent reviews have not changed based on data published during the subsequent years.