Few reports address the role of decompressive craniectomy in children with space-occupying cerebral edema attributable to severe ischemic infarction of the posterior cerebral arterial circulation. We describe four children with posterior circulation arterial ischemic stroke who required decompressive craniectomy. These children accounted for 11% of all cases of posterior circulation ischemic stroke at our institution from 2002-2010. Three manifested large, cerebellar hemispheric infarcts, and one manifested a large, temporo-occipital posterior cerebral artery infarct. Deterioration occurred within 72 hours of stroke onset. Two patients demonstrated minimal functional deficits at follow-up, and two demonstrated moderate deficits with functional limitations. Because decompressive craniectomy can be lifesaving in children with severe posterior circulation arterial ischemic stroke, early neurosurgical referral should be considered.