Perioperative neurocognitive disorders are common in elderly patients who have undergone surgical procedures. Neuroinflammation induced by microglial activation is a hallmark of these neurological disorders. Acetate can suppress inflammation in the context of inflammatory diseases. We employed an exploratory laparotomy model with isoflurane anesthesia to study the effects of acetate on perioperative neurocognitive disorders in aged mice. Neurocognitive function was assessed with open-field tests and Morris water maze tests 3 or 7 days post-surgery. Acetate ameliorated the surgery-induced cognitive deficits of aged mice and inhibited the activation of IBA-1, a marker of microglial activity. Acetate also reduced expression of inflammatory proteins (tumor necrosis factor-α, interleukin-1β and interleukin-6), oxidative stress factors (NADPH oxidase 2, inducible nitric oxide synthase and reactive oxygen species), and signaling molecules (nuclear factor kappa B and mitogen-activated protein kinase) in the hippocampus. BV2 microglial cells were used to verify the anti-inflammatory effects of acetate in vitro. Acetate suppressed inflammation in lipopolysaccharide-treated BV2 microglial cells, but not when GPR43 was silenced. These results suggest that acetate may bind to GPR43, thereby inhibiting microglial activity, suppressing neuroinflammation, and preventing memory deficits. This makes acetate is a promising therapeutic for surgery-induced neurocognitive disorders and neuroinflammation.