A 59-year-old man presented with gradual onset left sided facial numbness and vomiting. Over the following 7 days he developed stepwise brainstem deficits including left sided facial weakness, ataxia, nystagmus and bulbar weakness with absent gag reflex. The patient subsequently suffered respiratory arrest and was intubated. CT head was normal and lumbar puncture revealed CSF lymphocytosis with a mildly raised protein. Initial treatment included acyclovir and methylprednisolone. MRI head showed bilateral nodular ring enhancing lesions in the brainstem. The diagnosis of Listeria monocytogenes rhombencephalitis was made following positive blood cultures. Slow recovery began after initiation of amoxicillin. This case highlights key learning points. Listeria rhombencephalitis is a reversible cause of an evolving brainstem syndrome in immunocompetent patients, which when inadequately treated is associated with a high mortality rate. Diagnostic difficulty arises because initial CSF can be near normal and blood and CSF cultures are negative in 40% and 60% of cases respectively. This is an important differential diagnosis not to miss and empirical treatment with antibiotics in a patient with an evolving brainstem syndrome is recommended.