Introduction: Patients with perforation peritonitis present in the Emergency Department with various causes, but bowel perforation is the most frequent cause. These patients often arrive late at tertiary centres, resulting in severe peritoneal contamination and septic shock. Therefore, preoperative peritoneal drain placement provides adequate drainage and better outcomes in such cases. Aim: To compare various clinical and laboratory parameters in patients with perforation peritonitis before and after the placement of a peritoneal drain, prior to any definitive surgical treatment. Materials and Methods: A prospective cohort study was conducted in the Department of General Surgery at Kalpana Chawla Government Medical College in Karnal, Haryana, India, from October 2022 to June 2023. All cases of perforation peritonitis that were critically-ill or in shock upon presentation in the emergency department were planned for intraperitoneal drain placement before definitive surgery. A total of 140 patients were enrolled in the study, and their clinical parameters (temperature, pulse rate, SpO2, and urine output) and laboratory parameters (such as leucocyte count, electrolytes (Na+, K+, Ca++), pH, base excess, bicarbonate values, lactate, Random Blood Sugar (RBS), and haematocrit) were compared before and 24 hours after drain placement. Statistical analysis was performed using paired t-test. Results: The mean age of the patients was 46.03±18.06 years, and 116 (82.85%) of the cases were male. The most common comorbid condition was pulmonary disease {Chronic Obstructive Pulmonary Disese (COPD)/Asthma}, diagnosed in 96 (86.57%) cases. The most common perforation site was duodenal, followed by gastric and ileal, observed in 65 cases (46.42%), 23 (16.34%) cases, and 21 (15%) cases, respectively. There was a significant improvement in clinical parameters such as temperature, pulse rate, Saturation of Peripheral Oxygen (SpO2 ), and urine output after drain placement (p-value <0.001). There was also an improvement in laboratory parameters including leucocyte count, electrolytes (Na+, K+, Ca++), pH, base excess, and bicarbonate values (p-value <0.001). The mortality rate was 20%, with 28 cases resulting in death. Conclusion: Although preoperative intraperitoneal drain placement is not a standard surgical procedure for patients with perforation peritonitis, it resuscitates and stabilises the patient, thereby helping in reducing morbidity and mortality postoperatively.