Environmental non-profit organizations are the most active and effective actors in modern Russian society. To optimize the use of their potential insight into their performance is vitally important with little knowledge on the subject available at present. This article considers the organizational and legal forms, the location, and the priorities of the environmental non-profit organizations operating in the Irkutsk region in 2002–2014. The dynamics of number of such organizations and leading organizations is shown. In the beginning of the period under study non-governmental associations with non-commercial financing were mainly dominating, in the end they were non-profit commercial organization. Their ongoing work was largely linked to the protection of Lake Baikal that determined their interaction.