Web accessibility (WA) is an innovation in Web design; it can be considered as part of the corporate social responsibility (CSR) strategy of the firms. As adoption of innovations and CSR commitment are linked with firm size and national culture/legislation, we hypothesize that size and national culture/legislation, may have an effect on WA level. The authors studied an international sample made up of companies included in EUROSTOXX600 (The STOXX Europe 600 Index). The main results suggest that both size and culture have a significant effect on WA. Large firms as well as Anglo-Saxon companies are more prone to have higher WA levels. A deeper analysis, which was done through the estimation of quantile regression equations, showed that the influence of size is significant for companies trying to excel or for those trying to avoid the worst WA. However, the effect of size is significant only in the lowest part of the conditional distribution.