Introduction: Peritoneal carcinomatosis is a recurrence pattern in gastric cancer, commonly complicating the postoperative course, especially in high-risk individuals. These complications adversely affect quality of life, increase mortality, and have immediate postoperative clinical implications. Surgery is the best treatment for early-stage tumors, despite its associated risks, including mortality. Aim: To evaluate the impact of postoperative complications on the clinical outcomes of patients undergoing peritoneal cancer surgery. Methods: This cross-sectional observational study was conducted at the National Institute of Cancer Research and Hospital, Dhaka, Bangladesh, over twenty-one months from July 2017 to March 2019. Forty-two patients were selected based on inclusion and exclusion criteria and diagnosed clinically, radiologically, and histopathologically. Data were collected using a structured case record form and analyzed using SPSS-22. Results: The mean age of participants was 66.19 ± 10.38 years, with 33.3% aged 56-65 years. The cohort included 64.3% males and 35.7% females, with 52.4%, 40.5%, and 7.1% having a BMI of 18.5-24.9 kg/m², 25- 30 kg/m², and >30 kg/m², respectively. Smoking and betel leaf use were common (61.9% and 83.3%, respectively), with 69% from the middle class. Tumors primarily involved the proximal and distal stomach, with a mean size of 6.20 ± 1.86 cm, predominantly Type 3 and Type 4, and stages T4a and N2. No metastasis was observed. Total and lower radical gastrectomies were performed, with complications occurring in 9.5% (chest infection) and 14.3% (wound infection), while 76.2% had no complications. Conclusion: Complications can serve as indicators of postoperative clinical outcomes. The findings highlight the need for systemic changes in healthcare to reduce postoperative morbidity and mortality, thereby decreasing hospital stays.