External haemorrhoidal thrombosis (EHT) may be managed surgically or conservatively. The optimal treatment is, however, unclear, as is the long-term outcome following treatment. A literature search was undertaken to review and grade the evidence available for EHT management, determine the optimal management modality and assess long-term outcome after each treatment. Among 800 articles on haemorrhoids, only two prospective studies encompassing 248 patients and two retrospective studies of 571 patients were found. Excision significantly relieves presenting symptoms by postoperative day 4 compared with incision or topical GTN (Level IB evidence). Symptoms last over 3weeks with conservative treatment (Level III evidence) and this period may be reduced by combining topical nifedipine and lignocaine rather than using lignocaine alone (Level IB evidence). There is no evidence regarding the optimal time for non-surgical options. There is a remarkable paucity of studies on EHT and few of those available provide high levels of evidence. Surgery may be superior to conservative treatment but there is no evidence regarding the optimal period of initiation of conservative management. Prospective comparative studies are needed.