Aphasia constitutes a very complex clinical entity that requires a "competent" caregiver to interact with the person with aphasia (PWA). The literature lacks a valid and reliable set of standardized tools which can offer objective and quantifiable data of a caregiver's communicative competence. The aim of the study was to develop, standardize and validate an evaluation tool suited to measur the caregivers' competence in communicating with family members affected by aphasic disorders. Forty-two patients with aphasia and their respective caregivers were enrolled in the study. Caregivers' communicative competence was assessed through a new evaluation tool called ACCA-cl. Aphasia severity and functional communication abilities of the PWA were also investigated. Our data showed encouraging results regarding the reliability and the validity of the ACCA-cl scale in detecting the caregiver's communicative competence, especially as far as verbal content was considered. This scale can also be used to assess the improvement achieved by the caregiver after a communication training. The analysis provides encouraging findings for verbal content scales of the ACCA-cl and its possible use in clinical settings as a quantitative tool for detecting changes induced by the educational method of the caregiver. The tool is currently available in Italian.