Seroma is a common complication after inguinal hernia repair. There are great differences in the reported incidence of seroma, possibly because different scholars have different understandings of this condition. The patient's own factors, the surgeon's experience, and the materials of the mesh as well as its fixation techniques are all important causes for the formation of postoperative seroma. With regard to the treatment, clinical interventions are not needed in most cases because the seroma can be spontaneously absorbed, and only should be performed in few cases such as patients who have severe symptoms or infection. Thus, prevention is still the main strategy to reduce the incidence of perioperative seroma. Here, the authors review the research literature concerning postoperative seroma following surgery for inguinal hernia, so as to provide reference for clinical use.