Defendants often feign (i.e. simulate) dissociative amnesia for their crimes. The Symptom Validity Test (SVT) may be used to detect such feigning. Some studies have shown that feigning amnesia for a mock crime has memory-undermining effects. In this study, we wanted to replicate the memory-undermining effects of simulated amnesia. We also examined whether such effects would occur when participants' memories were evaluated with a SVT. Thirty participants committed a mock crime and then simulated amnesia for it. During a follow-up test, participants were instructed to perform as well as they could on a free recall test and a SVT. Their memory performance was compared with that of a control group (n =30). Although only a minority of simulating participants (7%) was detected by our SVT, the memory-undermining effect of simulating amnesia appeared to be a robust phenomenon. That is, ex-simulators displayed poorer free recall, more commission errors, and lower SVT scores relative to memory performance of honestly responding controls. However, at follow-up testing the poor memory of ex-simulators did not take the form of a real amnesia (i.e. random performance on SVT).