Separate lines of research have linked the temperament factor negative affect and perfectionism with internalizing disorders. Despite theory, no previous studies have connected these lines of research to examine internalizing pathology. The current study tested a path model to investigate the mediating effect of perfectionism domains on the relation between negative affect and child anxiety, worry, and depression symptoms. Participants were 61 parent–child dyads recruited from the community. Children were 7–13 years old (54.1 % male; 88.2 % Caucasian). Overall the model fit the data well. Analyses indicated that separate domains of perfectionism mediated separate relations between negative affect and child anxiety, worry, and depression symptoms. The findings suggest that domains of perfectionism may be implicated in specific paths between negative affect and child anxiety, depression, and worry. Implications and future directions are discussed.