Despite companies' wishes to publicise their corporate social responsibility (CSR) activities, communication remains a challenge. This research study tries to contribute to the literature, analysing the antecedents and consequences of attitude towards a CSR advertisement in the financial sector. Specifically, we designed a causal model, which included the prior ethical reputation, the range of possible attributions, and the mix of emotions provoked by the advertisement. We surveyed 225 adults in Spain who evaluated a fictitious advertisement for companies of different ethical reputations, conveying a philanthropic cause. As a result, it was observed that the advertisement generated a mix of intrinsic and extrinsic attributions and a mix of positive and negative emotions, and the prior ethical reputation of the company was a key antecedent of the effectiveness of the communication. Furthermore, a good attitude towards the advertisement has rewards, in terms of improvement of attitudes towards the brand and behavioural intentions. Copyright © 2017 John Wiley & Sons, Ltd and ERP Environment