The EIS has a Board with President, Vice-president, Secretary, Treasurer, and two members who are elected by the General Assembly meeting at Congresses, and an Executive Secretary, who is convenor of the forthcoming Congress. Several important society issues are handled by the Council , a 15-headed body elected by the membership. Society business meetings are known as the General Assembly, and realised at each Congress. Among other things the General Assembly elects the Board and Council, and decides about the membership fee. The current membership is about 50, but is believed to increase to more than 500 within a year.
Membership is open to any individual or corporate body interested in the aims of the society.
Membership is free for the period 1997-2000, but new members pay an inscription fee of USD 10.00. The Society issues an irregular Newletter, and published a directory of European fish collections in 1992. Members are entitled to reduced prices on several publications and may attend Congresses at lower rates. The activity schedule for the 1997-2000 period is in the planning, but will include a number of benefits.