An Energy Service Company (ESCO) is a firm that offers to reduce its client's energy bill, with the cost saving being split with the client. ESCOs in the full sense of the term offer finance for their projects, will accept the risk of the project and are remunerated in proportion to the savings achieved. On their part, clients may wish to contract out management of some or all of their energy affairs to save on management time and to benefit from the expertise and specialist knowledge of ESCOs. This paper is a record of the state of ESCO activity in Ireland in 2000, based on investigations undertaken for the European Commission's BARRIERS project. This project investigated barriers to energy efficiency. The finding on ESCOs was that there are few companies in Ireland that offer ESCO-type services, and that they fell into three groups. They consisted of (1) companies that offer contract energy management, (2) companies that are engaged in the supply of Combined Heat and Power, and (3) those that manage their clients' facilities. One company of each type was interviewed with a view to identifying barriers to their fuller development into ESCOs that would engage in energy saving activity.