A classical task of experimental psychology, the retention of lists of words, was given twice to three groups of subjects treated with lysine vasopressin (LVP), oxytocin or saline. From a baseline session (no treatment) to a second session with treatment, the LVP and placebo groups showed an enhancement of the number of words remembered correctly, whereas the oxytocin group did not. Rather, oxytocin impaired memory performance. However, we cannot claim a memory enhancing effect of LVP, because placebo treatment enhanced memory performance to the same extent.