Background: Gastrointestinal (GI) malignancies are among the most prevalent and challenging cancers in the world. Accurate staging of these cancers is critical in determining appropriate surgical interventions. Diagnostic laparoscopy (DL) has emerged as a minimally invasive tool to better stage malignancies, particularly when imaging modalities provide inconclusive results. This technique offers surgeons a direct visualization of the abdominal cavity, helping to assess resectability and avoid non-therapeutic laparotomies, thus reducing surgical morbidity and postoperative complications. Methods: In this observational study, conducted at ASRAM Medical College and Hospital from July 2022 to January 2024, 30 patients with gastrointestinal malignancies were evaluated. Patients were selected based on clinical, radiological, and histopathological suspicion of malignancy. Diagnostic laparoscopy was performed to assess the extent of tumour spread, with the primary aim of identifying unresectable disease and preventing unnecessary laparotomies. Data was collected on patient demographics, tumour characteristics, surgical outcomes, and cost effectiveness. Results: Among the 30 patients, diagnostic laparoscopy altered the treatment plan in 36% of cases, identifying unresectable disease that had not been detected by traditional imaging techniques. Laparoscopy prevented unnecessary laparotomies in 11 patients, thus significantly reducing the average hospital stay, postoperative complications, and healthcare costs. Conclusion: Diagnostic laparoscopy proves to be an effective and safe tool for staging gastrointestinal malignancies. It minimizes the need for non-therapeutic laparotomies, reduces patient morbidity, and provides a cost-effective approach to cancer management. The integration of DL into routine preoperative assessment for gastrointestinal malignancies is strongly recommended, particularly in cases where imaging results are inconclusive.