Reduction in the expression or function of [alpha]5-subunit-containing GABA[subscript A] receptors ([alpha]5GABA[subscript A]Rs) leads to improvement in several hippocampus-dependent memory domains. However, studies thus far mostly lack anatomical specificity in terms of neuronal circuits and populations. We demonstrate that mice with a selective knockdown of [alpha]5GABA[subscript A]Rs in CA1 pyramidal neurons ([alpha]5CA1KO mice) show improved spatial and trace fear-conditioning memory. Unexpectedly, [alpha]5CA1KO mice were comparable to controls in contextual fear-conditioning but showed an impairment in context discrimination, suggesting fine-tuning of activity in CA1 pyramidal cell dendrites through [alpha]5-mediated inhibition might be necessary for distinguishing highly similar contexts.