Objectives We describe the first application of intrauterine negative-pressure therapy (IU-NPT) for an early rupture of a uterine suture after a third caesarean section with consecutive peritonitis and sepsis. Because all four quadrants were affected by peritonitis, a laparotomy was performed on the 15th day after caesarean section. Abdominal negative-pressure wound therapy (A-NPWT) of the open abdomen was initiated. During the planned relaparotomy, a suture defect of the anterior uterine wall was identified and sutured. In the second relaparotomy, the suture appeared once more insufficient. Case presentation For subsequent IU-NPT, we used an open-pore film drainage (OFD) consisting of a drainage tube wrapped in the double-layered film. The OFD was inserted into the uterine cavity via the uterine defect and IU-NPT was established together with A-NPT. With the next relaparotomy, local inflammation and peritonitis had been resolved completely. IU-NPT was continued transvaginally, the uterine defect was sutured, and the abdomen was closed. Vaginal IU-NPT was also discontinued after another eight days. Conclusions By using IU-NPT, local infection control of the septic focus was achieved. The infectious uterine secretions were completely evacuated and no longer discharged into the abdominal cavity. As a result of the applied suction, the uterine cavity collapsed around the inlaid OFD. The total duration of IU-NPT was 11 days. The uterine defect was completely closed, and a hysterectomy was avoided. The patient was discharged four days after the end of IU-NPT. IU-NPT follows the same principles as those described for endoscopic negative-pressure wound therapy of the gastrointestinal tract.