Two experiments addressed the phenomenon of retrieval-induced forgetting (RIF) from the standpoint of cognitive energetics theory (CET). Consistent with the inhibitory account of RIF and with the notion that inhibition can be demanding and resource dependent, we found that where the inhibitory activity was difficult (vs. easy), defining a high restraining force according to the CET, RIF occurred only in the presence of a high driving force combining an elevated motivation to inhibit with the availability of high resources. Overall, the current work highlights the crucial role of motivation in producing the RIF and the way in which this phenomenon abides by the general principles of motivated cognition.