The majority of infants with multiple sutural craniosynostosis have identifiable syndromes, which affect both coronal sutures (Apert, Crouzon, Pfeiffer, and so on), and multiple sutural fusions not involving both these sutures are exceeding rare. We report a highly unusual pattern of trisutural fusion, which to our knowledge has not been previously described. A retrospective clinical review was performed of all cases of craniosynostosis, which had presented to the Craniofacial Center in Dallas, over a 15-year period. Two patients were identified with a unique pattern of craniosynostosis involving the left coronal, sagittal, and right lambdoid sutures creating a "Z-pattern." Both patients were treated with staged cranial vault reconstructive procedures with an initial posterior remodeling (3 to 4 months) followed by an anterior repair (7 to 8 months). Both patients developed cerebellar tonsillar herniation, and one symptomatic patient required surgical decompression. With a follow up of greater than 2 years, normocephaly has been maintained with growth, and both children appear to have normal intellectual development. A unique pattern of trisutural "Z-patterned" craniosynostosis is presented. This distinctive pattern of craniosynostosis appears to be associated with cerebellar tonsillar herniation. In this small series, a two-staged procedure successfully normalized the calvarial dysmorphism, and early growth and development appear normal.