Simple Summary There continues to be little research in the literature on perioperative outcomes after cytoreductive surgery (CRS) combined with intraoperative hyperthermic chemotherapy-lavage (HITOC) in patients with malignant pleural tumours. The aim of this multicentre study was to assess the results of the current practice in Germany so as to give recommendations to standardize the procedure. CRS with cisplatin-based HITOC can be performed with low major morbidity and a low rate of renal insufficiency, which was associated with the cisplatin dosage of irrigation. In the context of quality assurance, the objectives were to describe the surgical treatment and postoperative morbidity (particularly renal insufficiency). A retrospective, multicentre study of patients who underwent cytoreductive surgery (CRS) with cisplatin-based HITOC was performed. The study was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation (GZ: RI 2905/3-1)). Patients (n = 350) with malignant pleural mesothelioma (n = 261; 75%) and thymic tumours with pleural spread (n = 58; 17%) or pleural metastases (n = 31; 9%) were analyzed. CRS was accomplished by pleurectomy/decortication (P/D: n = 77; 22%), extended P/D (eP/D: n = 263; 75%) or extrapleural pneumonectomy (EPP: n = 10; 3%). Patients received cisplatin alone (n = 212; 61%) or cisplatin plus doxorubicin (n = 138; 39%). Low-dose cisplatin (<= 125 mg/m(2) BSA) was given in 67% of patients (n = 234), and high-dose cisplatin (>125 mg/m(2) BSA) was given in 33% of patients (n = 116). Postoperative renal insufficiency appeared in 12% of the patients (n = 41), and 1.4% (n = 5) required temporary dialysis. Surgical revision was necessary in 51 patients (15%). In-hospital mortality was 3.7% (n = 13). Patients receiving high-dose cisplatin were 2.7 times more likely to suffer from renal insufficiency than patients receiving low-dose cisplatin (p = 0.006). The risk for postoperative renal failure is dependent on the intrathoracic cisplatin dosage but was within an acceptable range.