Pancreatic mucinous cystic neoplasms are uncommon and their occurrence in pregnancy is extremely rare. The authors report the unique case of a newborn weighing 3,620 g, delivered vaginally with no complications by a patient with a large ‘silent' pancreatic mucinous cystic neoplasms, and analyze the very few other reports. With no available protocol, this case highlights an interesting dilemma on the management of pregnancy and delivery as well on the timing of pancreatic surgery. Despite its limitations, MRI remains the most accurate investigation either for differentiating the mucinous from nonmucinous cysts or for evaluating the malignancy, but echography is also very useful. Without symptoms, all low-grade malignant potential tumors, independent of the moment of their diagnosis during pregnancy, should be resected 2-3 months after delivery and we believe that the best option is a term vaginal birth, even in the presence of a large cyst and large fetus. On the contrary, all high-grade malignant potential tumors, discovered in the first two trimesters of pregnancy should be resected during the second trimester, and followed by a vaginal delivery at term. If high-grade malignant potential tumor is diagnosed in the third trimester, an early vaginal delivery followed by surgery is recommended. Finally, the patient's preference is crucial.