Objective This study aimed to examine cognitive function in individuals with anorexia nervosa (AN) and bulimia nervosa (BN) on the basis of IQ measures, indexes and subtests of the Wechsler Adult Intelligence Scale – Third Edition (WAIS‐III). Methods A total of 41 patients with AN, 40 patients with BN and 40 healthy controls (HC), matched for sex, age and education, were recruited consecutively to complete the WAIS‐III. Results The AN group showed a significantly lower performance than the HC group on most global measures and on eight of the 13 administered subtests. Minor differences in verbal function were detected between the BN group and the HC group. Conclusion The patients with eating disorders showed normal intellectual functions compared with the normative population. However, the AN group displayed a consistently lower performance than the matched HC group, which performed above normative means. The BN group performed at a level between that of the AN and HC groups. Copyright © 2013 John Wiley & Sons, Ltd and Eating Disorders Association.