Objective To evaluate the methods and effects of clinical treatment strategies of 43 cases of contralateral traumatic subdural hygromas after one side hemicraniectomy. Methods We retrospectively analyzed 43 cases of clinical data. All the patients were treated by conservational treatment.Among of them,19 cases were treated by surgical treatments at last.Results Among of these 19 cases,4 cases were evolved into chronic subdural hematomas finally.In 15 cases treated by surgical treatments,subdural hygromas disappeared totally in 10 cases treated by subdural external drainage. 5 cases were unchanged and then they were treated by subdural to peritoneal shunt.Whereas one patient were treated by sylvian arachnoid ostomy via pterional keyhole approach because of shunt blockage.Conservational treatments cure rate was 55.8%. Conclusions The patients of traumatic subdural hygromas should be treated by conservational treatments first.Surgical treatments including subdural external drainage,subdural to peritoneal shunt and sylvian arachnoid ostomy via pterional keyhole approach are safe and effective ways for traumatic subdural hygromas.