Corporate Social Responsibility (CSR) is understood as liabilities a person or organization has towards its social context, including people as well as physical environment, when conducting any activity whose consequences will not only affect the subject who carries it out. However, there has been scarce attention in academia and practice to CSR's influence on brand awareness. To shed light on this issue, this study gives insight on the effect CSR reporting initiatives and effective communication has in consumer's perception and knowledge of a company's brand. To achieve this goal, 16 of Spain's most renowed and well known service companies were considered, including a wide range of service-related sectors: airlines; transportation; tourism and leisure; bank and financial services; insurance; gas, petrol and electric suppliers; retailers and private security. CSR variables were measured by considering i) holding ISO 26,000 certification; ii) whether the firm is privately or state-owned; and iii) global reporting initiative (GRI) report review organism. We also controlled with the variable joining the carbon disclosure project (CDP). Findings prove the positive association between ISO 26,000 with the firm's brand awareness. Notwithstanding this, our results show private ownership firms have a negative impact on brand awareness. Considering public sector can tackle broader topics, influence greater communities and engage a greater number of stakeholders, these findings result consistent. Furthermore, it was shown that reported information being reviewed by organisms other than GRI organism is positively associated with the company's brand awareness in the service sector. This will be our contribution.