Rats with medial septal lesions and sham operates were run in a straight runway. After running stabilized, food was omitted on selected trials and the running speed on the following trial was observed for a frustration effect (FE). The septals exhibited a significantly greater increase in speed on this trial than controls. This enhanced FE in septals is at variance with predictions from frustration theory considering the greater resistance to extinction in septals and suggests a dissociation between the immediate and conditionable effects of frustration in such animals. © 1975.