This research examines the influence of types of protest activities, Congressional hearings and political characteristics on environmental legislation enacted from 1961-1990. We find that rates of environmental protest rise with increases in the amount of previous institutional activities, but extra-institutional activities do not raise the overall rate of protest. Protest has no direct effect on the passage of legislation, but institutional protest activities significantly raise the rate of Congressional hearings on the environment. When comparing all environmental laws to those designated as having a major impact, we find both similarities and differences. For example, prior legislative activity decreases both rates, but increases in criteria air pollutants and partisan characteristics of Congress significantly affect only the rates of major environmental legislation. (Contains 1 figure, 4 tables and 12 notes.)