Cases of digestive cancers diagnosed during pregnancy are rare. The increasing prevalence of pregnancy in women aged 30–39 years (and not exceptionally 40–49 years) could explain the frequent co-occurrence of cancers and pregnancy. The diagnosis of digestive cancers in pregnancy is difficult due to the overlap between neoplasm symptomatology and the clinical picture of pregnancy. A paraclinical evaluation may also be difficult depending on the trimester of the pregnancy. Diagnosis is also delayed by practitioners’ hesitation to use invasive investigations (imaging, endoscopy, etc.) due to fetal safety concerns. Therefore, digestive cancers are often diagnosed during pregnancy in advanced stages, where complications such as occlusions, perforations, and cachexia have already arisen. In this review, we highlight the epidemiology, clinical aspects, paraclinical evaluation, and particularities of the diagnosis and treatment of gastric cancer during pregnancy.