In two experiments, we examined memory for event frequency among depressed and/or elderly subjects (depression was either naturally occurring or induced by the Velten technique). We also manipulated level of processing and instructional set to test the notion that memory for event frequency is relatively invariant across a variety of tasks. Results supported the proposal that memory for frequency is robust in the face of depression and old age. Memory for frequency was enhanced, however, by semantic processing and by an intentional learning instructional set. Finally, the results suggest that the Velten technique not only induced variation in mood but also may have induced a semantic processing strategy in our depressed and elated subjects.