The quality of information is essential for the survival of any institution, which is why Health Services need quality systems that effectively meet the demands of their users. The quality of the e-Vaccines was assessed through the Data Quality Assessment methodology in two districts of Alentejo, which revealed that this information system plays an important role in the quality of care delivery, particularly in vaccination at the level of efficiency and effectiveness of service to users and in reducing the risk of errors. The e-Vaccines is a quality system, since the assessment of the four dimensions proposed by the authors revealed a global result considered strong, also demonstrating that this application is an essential work tool in care delivery, facilitating communication and the information sharing, thus promoting the existence of coordinated interventions among professionals.