Pneumatosis cystoides intestinalis (PCI) is a rare gastrointestinal complication of systemic sclerosis (SSc) characterized by intramural accumulation of gas within thin-walled cysts. We report the case of an 82-year-old female patient with pneumoperitoneum due to PCI associated with SSc and review the features of the 39 Japanese cases. The median patient age was 57 years (range 24-83 years) and the male/female ratio was 1 : 12. In the recent decade, 14 out of 15 cases (93.3%) evaluated with CT scans were diagnosed with PCI. The results suggest that CT scan may be a useful diagnostic tool for detecting PCI. PCI in patients with SSc is usually benign and requires only conservative therapy. However, two patients (5.1%) with signs of peritoneal irritation required surgery. When peritoneal irritation secondary to additional pathology is observed, surgical treatment may be warranted; a precise diagnosis for this condition is therefore essential.