Firms are implementing Customer Relationship Management (CRM) systems not for reducing their operational costs and increasing their efficiency, as it happens with other kinds of information systems, but in order to offer better services to their customers and build better relationships with them. This fact stems from CRM’s customer facing nature, which is there to improve the relationship a firm has with its most valuable asset: the customers. However, there is limited research about the factors that lead firms to adopt CRM systems. This paper aims to contribute to filling this research gap, by investigating the effects of a wide range of factors on CRM adoption by firms; these factors include firm’s ICT resources and capabilities, and also the effects of a major disruption in the environment: economic crisis leading to recession. Our main theoretical foundation is the Technology, Organization, Environment (TOE) theory of technological innovation adoption. Based on data from 363 Greek firms CRM adoption models have been estimated, which indicate that the sophistication of firm’s ICT technological resources has a strong positive effect on CRM adoption, alongside two ICT capabilities: ICT strategic planning, and the rapid internal implementation of various interconnections/integrations of existing applications to achieve interoperability. Human capital, innovativeness and use of ‘organic’ forms of work organization (such as horizontal teamwork) are also important factors that affect positively CRM adoption. On the contrary, the effects of the economic crisis (decrease of domestic demand for products/services from businesses, individual customers and the public sector, reduction of credit limits by banks and non-payment or late payment by customers) do not have impact on CRM systems adoption.