An unusual case of communicating, tubular gastric duplication (GD) of the greater curvature of the stomach presenting with pneumoperitoneum is described. The pneumoperitoneum resulted due to simultaneous mechanical rupture of stomach and its duplication cyst due to birth trauma and vigorous post delivery resuscitation. No case of this kind has been reported earlier in English literature, though instances of ulcerative perforation of neonatal stomach and GD are known. There was radiographic evidence of multiple thoracic vertebral anomalies, again a rare occurrence with GD cyst. Further, a diagnostic dilemma was faced in this patient as the presence of radiographic sign of "gastric bubble" on plain radiographs in this patient suggested the source of free intraperitoneal air to be extragastric and the diagnosis could be made only at surgery. The authors have reviewed the pertinent literature on neonatal gastric perforation and GD cysts and uphold "split notochord" theory as etiology for GD in this patient.