Background: Oxaliplatin hypersensitivity is not uncommon in patients with gastrointestinal (GI) cancers receiving chemotherapy. The use of oral premeditations (dexamethasone, cetirizine and famotidine) starting 24 hours before treatment and continuing for a total of three days, further intravenous premedication (dexamethasone, chlorphenamine and famotidine) 30 minutes before treatment and the gradual administration of oxaliplatin over 6.5 hours in four separate escalating doses (desensitisation protocol) is commonly used in such cases. While desensitisation is an option, especially in severe cases, responses and survival outcomes upon rechallenge are not well described. Methods: A retrospective chart review of patients with various GI malignancies who received oxaliplatin-based desensitisation chemotherapy after a severe drug reaction between October 2019 and October 2022 at a single cancer centre was performed. Clinicopathological characteristics and oncological outcomes were assessed. Results: Forty-four patients with a median age of 61 years (range 38-81) were studied. The majority had a diagnosis of CRC (n=22; 50%), followed by oesophago-gastric (n=19; 4%), appendiceal (n=1), cholangiocarcinoma (n=1), and cancer of unknown primary (n=1). More than two thirds of patients (n=32, 73%) were treated with palliative intent. The most common regimens associated with oxaliplatin hypersensitivity reactions after a median of 3 cycles (range 1-10) were FOLFOX (n=24, 55%), CAPOX (n=18, 41%), FLOT (n=1) and FOLFOXIRI (n=1). Seven patients (16%) had another reaction after desensitisation, leading to discontinuation of treatment. Thirty-seven patients (84%) completed treatment as planned. Treatment outcomes after desensitisation included 5 (11%) patients with no evidence of disease (NED) after adjuvant treatment, 16 (37%) patients with disease control, including 3 (7%) partial responders (PR) and 13 (30%) patients with stable disease (SD), and 23 (52%) patients with progressive disease (PD). Conclusions: Oxaliplatin desensitisation is feasible with low discontinuation rates and leads to acceptable oncological outcomes. All patients should be offered desensitisation to allow continuation of active systemic therapy.