Background: Hypertension is characterized by persistent high blood pressure and has emerged as a critical risk factor for severe cardiovascular diseases. Although several drugs have been designated to reduce blood pressure, these drugs can potentially cause side effects for patients. Therefore, medicinal plants are used to complement conventional drugs to treat various ailments. Method: This study reviews the anti-hypertensive potential of herbs and plants and their mechanism of action in reducing blood pressure at their evaluated effective doses. Databases such as PubMed, Scopus, Science Direct, and Google Scholar were used to search articles from January 2016 to Sept 2022. The key search terms included “hypertension”, “lowers blood pressure”, “anti-hypertensive”, and “plants”. These generated 807 documents and using the PRISMA guidelines, thirty plants were identified for this review. Research studies with similar plant parts extracted from similar solvents, more than one dose, and animal models with a positive control were considered in this review. Studies that did not show significant blood pressure reduction were excluded. Result: Based on this criterion, the mechanism of actions of these plants was thematically grouped into three categories, namely 1) antioxidant, 2) angiotensin-converting enzyme (ACE) inhibition, and 3) calcium influx in vascular smooth muscle. The effective doses, plant parts used, and traditional medicine usage are presented in this review. Conclusion: Further research is highly recommended to identify the active compounds and to potentially develop them into anti-hypertensive drugs as well as to establish the safe doses and standardization of these plant extracts. This review is partially funded by grants from the Ministry of Higher Education.