Vascular oxidative stress, inflammatory response, and proliferation are crucial mediators of vascular dysfunction which contribute to the pathology of hypertension. A tripeptide, LRW (Leu-Arg-Trp), was characterized from pea protein legumin, and its previously studied isomer IRW (Ile-Arg-Trp) was reported to exhibit antihypertensive activity via activation of angiotensin-converting enzyme 2. The objective of the current study was to explore the effects of LRW on vascular stress in vascular smooth muscle cells (VSMCs) under angiotensin II (Ang II)-induced cellular stress. LRW treatment could decrease Ang II-triggered superoxide production, inflammation, and proliferation in VSMCs. The abovementioned advantageous effects appeared to involve the upregulation of the ACE2-Ang-(1-7)-MasR axis and modulation of the nuclear factor-κB pathway. These findings specified the prospective role of LRW as a functional food ingredient or nutraceutical in the prevention of cardiovascular diseases, particularly hypertension and vascular damage.