Seromas are common after minimally invasive and open surgery for inguinal, ventral and incisional hernias and are considered a complication in most literature reports. The incidence of postoperative seromas is highly variable, as different criteria are used for diagnosis and description. For this reason, it is important to establish a correct definition and classification in order to determine the actual prevalence and prognosis. Various intraoperative strategies to minimize the seroma rate have been described: on the one hand, surgical steps on the hernia sac itself (e.g. resection, electrocautery, sclerotherapy with the argon beamer), and on the other hand, strategies to reduce the dead space (e.g. sealing with fibrin glue, shirring of the hernia sac left in place, placement of a preventive drainage). However, primary fascial closure in ventral and incisional hernias is probably the most promising strategy for reducing postoperative seromas. Most seromas are asymptomatic and do not require treatment. However, when seromas cause symptoms, they need to be treated. Sometimes it may even be necessary to puncture and drain to relieve symptoms or treat infection. Removal of the mesh as a last therapeutic option is only necessary in very rare cases.