Sepsis is characterized by an intense inflammatory reaction with potential neurotoxic effects in the central nervous system and damage to memory and learning ability. We assessed the effects of acute low dose of MK-801 on the memory impairment, hippocampal BDNF levels and DARPP-32 expression ten days after sepsis. Under anesthesia, male Wistar rats underwent either cecal ligation and perforation (CLP) or sham. Then, the animals received either a single systemic injection of MK-801 (0.025 mg/kg) or saline solution. Ten days after CLP, the animals were submitted to the step-down inhibitory avoidance and object recognition tests. Also, the hippocampal BDNF protein levels and DARPP-32 expression were evaluated. MK-801 prevented cognitive impairment, but did not affect the hippocampal BDNF levels. DARPP-32 expression was significantly different only in the animals submitted to sepsis that received MK-801 treatment. Thus, we demonstrated that a single low dose of MK-801 prevented memory impairment without altering hippocampal DARPP-32 expression and BDNF levels.