Purpose To study the enhancement pattern of differentiated and undifferentiated gastric carcinoma on multiphasic contrast-enhanced computed tomography (CT). Material and methods Seventy patients with biopsy-proven gastric cancer underwent multiphasic contrast-enhanced CT. The CT protocol include plain, arterial, portal venous, and hepatic venous phase. Tumour size, location, peak-enhancement characteristics, and staging were evaluated. Results The peak-enhancement type was ‘arterial’ in 20 out of 28 within the differentiated-type GCAs and ‘portalvenous’ in 37 out of 42 within the undifferentiated-type GCAs (c 2 statistic with Yates correction = 23.3981, p < 0.00001). The maximum attenuation value was statistically significant for the arterial phase between differentiated and undifferentiated GCAs ( p < 0.05). Conclusions Assessing peak-enhancement in a multiphasic CT can help identify the histological subcategory of gastric carcinomas that has prognostic significance. Arterial phase peak-enhancement is frequently seen in differentiated carcinomas whereas venous phase peak-enhancement is seen in undifferentiated carcinomas.