CSR has been a more popular subject in the last few decades. However, CSR is seldom connected with SMEs. Many scholars suggest that the reasons are: firstly the attention on CSR practice falls much more on MNCs since publics perceive MNCs have bigger impact on the society. Secondly, most SMEs do not have required resources to work with CSR and many SMEs regard CSR as a burden. However, there are more and more SMEs that start to work with CSR. Therefore the purpose of this thesis is to increase the understanding of why SMEs work with CSR and how do SMEs implement CSR strategies.   The theoretical framework contains strategy, CSR pyramid, decision making process, stakeholder theory, business opportunity model of CSR for SME, legitimacy, strategy implementation and business relations. The emiprical findings contain the case firms’ view on what stimulate them to work with CSR and how they implement its CSR strategies within and outside the firms.   In the analysis we have connected the theoretical framework with our empirical findings. We analyze who the decision makers are and most important stakeholders within the firm as well as what stakeholders are interested in to be able to answer our firs research quesiton. Furthermore, we describe the implemetion process of our case firms as well as to analyze what types of business relations they have wirh its supplier, which will help us to answer our second research question.   The conclusions of this thesis are that it is profitability that drives SMEs to work with CSR. Furthermore, SMEs carry out its CSR strategy differently and the differences depend on how much resources do firms have and the types of relationship with suppliers.