The purpose of this study was to compare bulimia nervosa (BN) and substance use disorders (SUD) in cognitive-motivational terms. The cognitive orientation theory was used as a framework for testing the hypothesis that the commonality between BN and SUD consists of a similar motivational disposition for eating disorders, rather than for addiction, as was previously claimed. It was expected that BN and SUD patients would differ from controls but not from each other. The participants were 31 BN, 20 SUD, and 20 healthy controls. They were administered questionnaires for assessing anxiety, depression, addiction and the cognitive orientation for eating disorders. On most parameters BN and SUD scored higher than controls but did not differ from each other except in norm beliefs. Treatment of BN should consider the similarity of BN to SUD in the pathological tendency for eating disorders.