The objective of this review is to assess the clinical evidence for or against cupping as a treatment for hypertension. We searched the literature using 15 databases from their inception to 30 June 2009, without language restrictions. We included all clinical trials (CTs) of cupping to treat hypertension in human patients. Risk of bias was assessed using the Cochrane criteria. Two CTs met all inclusion criteria. One RCT (randomized CT) assessed the effectiveness of dry cupping on changes in cerebral vascular function compared with drug therapy. Their results suggested significant effect in favor of cupping on vascular compliance and degree of vascular filling. One uncontrolled observational study (UOS) tested wet cupping for acute hypertension and found that a one-time treatment reduced blood pressure. In conclusion, the evidence is not significantly convincing to suggest cupping is effective for treating hypertension. Further research is required to investigate whether it generates any specific effects for that condition.