This study examined the influence of maternal anxiety on the treatment outcome of anxious children. Forty-eight clinically anxious children (aged 6–14 years) were classified into two groups based on the presence of an anxiety disorder diagnosis in their mother. Diagnostic data at posttreatment showed that children with anxious mothers responded significantly less favourably to cognitive behavioural therapy (CBT) than did children with nonanxious mothers (28% vs. 58% improved, respectively). At 12-month follow-up, 68% of children with anxious mothers improved, compared to 79% of children with nonanxious mothers. This difference was not significant. Findings were not consistent across outcome measures. This study also investigated the changes in maternal anxiety across child treatment. Prior to treatment, diagnostic data showed that 60% of mothers met criteria for an anxiety disorder. At posttreatment, 21% of these mothers were free of their primary diagnosis. There was also a significant reduction in self-reported maternal anxiety across treatment that was maintained at follow-up. Theoretical and clinical implications of the findings are discussed.