An environmentally significant measure of household consumer behavior (i.e., combined direct and indirect energy use) is presented and compared with a common social science measure of proenvironmental behavior (based on popular notions of environmentally significant behavior). Two large-scale field studies (Study 1-2,167 Ss; Study 2-1,250 Ss) were conducted among representative samples of Dutch households. The results show respondents who indicate they behave more proenvironmentally do not necessarily use less energy. Also, proenvironmental behavior is more strongly related to attitudinal variables, whereas household energy use is primarily related to variables such as income and household size. More multidisciplinary research seems necessary to identify variables that influence the actual environmental impact of household consumer behavior. Estimations of energy use related to household consumer behavior are appended.