Objective The prevalence of the non-convulsive type of late seizure after stroke is unknown. The aim of the present study was to clarify the characteristics of late seizure in clinical practice, mainly focusing on the prevalence of non-convulsive seizure. Methods A total of 178 consecutive patients who were admitted and diagnosed with late seizure after stroke were retrospectively enrolled, and the data of 127 patients for whom the complete seizure was observed by a bystander were analyzed. Clinical information was obtained from the medical records and nursing notes. Results A non-convulsive seizure was observed in 37 patients (29%). A focal seizure and its secondary generalization accounted for 79% of the seizure types. Status epilepticus was observed in 60 patients (47%), including 11 patients (9%) without convulsion. The patients with non-convulsive seizures were significantly younger than those with convulsive seizures, but there were no other significant differences between the two groups with respect to sex, classification or the lesion of stroke. Conclusion There was a high rate of non-convulsive seizures in patients with late seizure after stroke. A non-convulsive seizure may be caused by any type or location of preceding stroke. More attention is needed in the differential diagnosis of neurological deterioration after stroke.