Lubeluzole, the S-isomer of a novel difluorobenzothiazole, is a neuroprotective compound aimed at the treatment of acute ischaemic stroke. In a photochemical stroke model in rats, in which a neurological test was designed that is also relevant to other stroke models, intravenous posttreatment with lubeluzole stereoselectively rescues sensorimotor function (time window of 6 h) and reduces infarct size. Posttreatment with lubeluzole also reduces infarct size after middle cerebral artery occlusion in rats, attenuates delayed neuronal death after global ischaemia, and may also act on mechanisms of cerebral oedema. The compound normalizes peri-infarct neuronal excitability and blocks the rise of peri-infarct extracellular concentration of glutamate. Lubeluzole downregulates the nitric oxide synthase (NOS) pathway leading to neurotoxicity and neuronal death. NOS pathway modulation may contribute to the neuroprotective properties of lubeluzole.