This study investigated the interaction between physiological arousal and situation-derived cognitions in the determination of feeling states that is proposed in Schachter's theory of emotions. The degree of bodily arousal was varied by disguised oral administration of a placebo or the sympathicomimetic agent ephedrine. The situational circumstances were varied by instructions offering cues for (a) no emotions ('neutral' control), or the feeling states called (b) 'anger', (c) 'happiness', and (d) anxiety'. The subjects were 72 male students. The dependent variables were blood pressure, heart rate, a list of bodily symptoms, and an adjective check list. The results within the 'anger' and 'happiness' condition were in accordance with Schachter's theory: depending on the type of situation, ephedrine-induced arousal either decreased or increased positive descriptions of mood. The emotional effects of the 'anxiety' condition, however, were independent of the drug-induced arousal level. Contrary to Schachter's theory, anxiety reactions occured also in a state of low physiological arousal and did not increase with increasing arousal.