False autobiographical remembering is known to be affected both by an event's emotional valence and its perceived frequency (PEF). Here, we present a procedure that enables the assessment of retrieval accuracy for details of an overarching personally relevant real‐life event (a graduation ceremony) while taking into account variations in both their valence and PEF. Former university students who attended the same graduation ceremony completed a questionnaire with true and false statements about the ceremony. Their task was to judge whether the event details were true. Event details were previously rated for valence (positive vs. negative) and PEF (high vs. low) and their truth status was confirmed with original video footage from the ceremony. The results showed that valence modulated the effect of PEF on memory accuracy in that a decrease in false memory judgements was observed only for negative low‐PEF (implausible) event details. These results are interpreted within the affect‐as‐information framework. Copyright © 2016 John Wiley & Sons, Ltd.