Our work would like to discover whether certain performance indicators are affected by a firm’s social responsible behaviour and their certifications by looking at panel data. The novelty of our analysis is due to its dynamic aspect and from a CSR index that intersects two of the three main international indices (Domini 400 Social Index, Dow Jones Sustainability World Index, FTSE4Good Index), to be objective and obtain a representative sample. The main results seem to support the idea that CSR firms which are more virtuous, have better long run performance. They have some initial costs but obtain higher sales and profits due to several causes reputation effect, a reduction of long run costs and increased social responsible demand