Factor XII (FXII) plays a pivotal role in hemostasis, inflammation and complement system. Its deficiency is usually an incidental finding in an otherwise asymptomatic patient who is identified during his/her routine preoperative blood work. This study aimed in evaluating the clinical course of the surgical patients having FXII deficiency. Information regarding demographics, laboratory tests and management of patients was obtained through medical chart and in-house integrated laboratory management system whereas the medical literature was searched through PubMed®. During the study period, two patients were consulted for FXII deficiency prior to the various surgical procedures. Both patients had uneventful surgeries without any thrombotic events while hemorrhage observed in one patient was secondary to obstetric complications. With the limited evidence today, it is concluded that patients having FXII deficiency are not at increased risk of bleeding, thrombosis or infections during surgery, but a personalized approach is needed for planning an appropriate perioperative management.