Anxiety disorders are highly prevalent among school-aged children. These disorders become chronic in a substantial proportion of youths and cause significant interference with daily functioning. The purpose of the current investigation was to examine the psychometric properties of the Portuguese version of the Child Anxiety Life Interference Scale – Parent and Child versions (CALIS-P and CALIS-C). The sample consisted of 132 children between the ages of 7 and 12 with a main diagnosis of anxiety disorder and their parents. A factor analysis of the CALIS-P yielded three factors that agreed with the hypothesised subscales of At Home, Outside Home and Parent Life interference. For the CALIS-C, a factor analysis yielded two factors corresponding to Close Relationships and Performance interference that did not match the subscales of the original version. The internal consistency of the various CALIS subscales was good. Finally, evidence was found for both convergent and divergent validity. The CALIS scores were also significantly correlated with another measure of interference. The results provide initial support that the Portuguese version of the CALIS is a reliable and valid measure for the assessment of the impact of anxiety on child and family functioning.