Background: Chemotherapy-induced nausea and vomiting (CINV) is a bothersome side-effect associated with cancer chemotherapy which adversely impacts both quality of life and the ability to carry out the activities of daily living. This study was conducted to assess the proportion of patients developing CINV after receiving chemotherapy for gastrointestinal (GI) cancers, in spite of receiving antiemetic prophylaxis as per the standard guidelines. Methods: Consecutive patients with GI malignancy who had not received previous chemotherapy were eligible for enrollment in the study if they were scheduled to receive at least one cycle of chemotherapy. SPSS version 20 was used for all statistical calculations. Results: 701 patients fulfilling the eligibility criteria were included in this study, out of which 55.4% were males, median age was 51 years (range 22-77). Biliary tract cancer (34%) was the most common diagnosis followed by colorectal (30.2%) and gastric cancer (19.6%). As per MASCC guidelines, 22.1% patients received highly emetogenic chemotherapy, 56.0% moderately emetogenic chemotherapy (MEC) while 19.9% received regimen with low emetogenicity. Failure to achieve complete response (CR, absence of acute and delayed CINV) was found in 27.4% patients. On separately analysing MEC group, overall CR was not achieved in 33.8% with failure in acute settings in 17.8% and delayed in 16.0% patients. Only significant factor for not achieving CR was use of oxaliplatin based chemotherapy (p = 0.018 for acute and p = 0.014 for delayed CINV). Conclusions: More than one fourth patients failed to achieve complete response for CINV in gastrointestinal cancers despite using prophylaxis as per standard guidelines. Use of oxaliplatin based therapy is an important factor for MEC causing CINV. There is urgent need to update the guidelines for prophylaxis in this setting.