One hundred eight carrier mothers (95 premutation, 13 full mutation) of children with the full mutation fragile X syndrome completed seven scales to assess maternal stress, depressive symptoms, anger, anxiety, quality of life, hope, and optimism. A wide range of responses was found on each measure, with most mothers scoring in the non-clinical range on any individual measure. However, nearly half of the mothers scored in the clinically significant range on at least one measure and 25% on two or more measures. High stress and low quality of life were the most common domains of concern. Mothers with the full mutation generally did not differ from mothers with the premutation. CGG repeat length was not associated with responses on any of the measures completed by mothers with the premutation. Severity of the child's delay was not associated with any of the outcome measures, but child behavior problems accounted for significant variance in stress, depressive symptoms, anxiety, anger, and quality of life. Maternal adaptation appears to be a multidimensional phenomenon experienced in unique ways by each mother. Most mothers experienced positive adaptation, but a subset appear to be more vulnerable, especially those with children who have significant behavior problems. Future research needs to identify family, child, and support factors associated with maternal vulnerability and how adaptation changes over time in response to these factors. © 2008 Wiley-Liss, Inc.