OBJECTIVE: To obtain a better understanding of the clinical course and the subsequent complications of teratoma rupture.CASE: We report a rare case of chemical peritonitis and pleuritis caused by teratoma rupture during ultrasonographically guided transvaginal oocyte retrieval (TVOR). The patient initially presented with nonspecific and digestive symptoms after TVOR, but the condition deteriorated rapidly after three weeks with peritonitis and septic shock. Thus, exploratory laparoscopy was performed with the findings of a ruptured teratoma at left adnexa, severe adhesions, and purulent fluid in her peritoneal cavity. Bilateral pleuritis was also noted after the operation, which was suspected to be caused by chemical irritation of the spilled contents of the teratoma. The patient's condition improved after surgical treatment and was discharged 28 days after admission.CONCLUSION: Our case showed that the timing of peritoneal irritation caused by teratoma rupture converting to severe chemical peritonitis was approximately 3 weeks. Physicians should avoid cyst puncture during TVOR and closely observe or even perform surgical treatment when iatrogenic teratoma ruptures are suspected.