This book aims to describe and classify environmental non-governmental organizations in Turkey. In the data-gathering phase of the study face to face interviews were conducted with the staff and heads of environmental non-governmental organizations panels and meetings were attended. After reviewing alternative definitions and classifications of non-governmental organizations the classification framework has been based on six main criteria: legal structures objectives action areas orientations geographic distributions and relations with government. Furthermore the study addresses the rapid growth of environmental non-governmental organizations in number and diversity and explains the reasons of this increase as the changing policies of governments the increase in international financial aids to the NGOs and the growing environmental problems between 1980 and 2000.