Tamoenju (Hibiscus surattensis L.) is one of the ethnomedicinal plants used in treating hypertension. One of the potential antihypertensive mechanisms includes angiotensin-converting enzyme ACE inhibitors, considered the firstchoice treatment for hypertension. This research presents a physicochemical, phytochemical, and ACE inhibitory activity test of tamoenju leaf extract (TLE). The leaf extract was evaluated to determine the physicochemical and phytochemical profiles using standard methods. The physicochemical evaluation indicated 20.66 ± 3.51% water content, 26.67±5.77% drying shrinkage, 2.0 ± 1.0% total ash value, 0.30 ± 0.13% acid insoluble ash value, 20.00 ± 4.00% water soluble extractive value, 57.00 ± 4.61% alcohol soluble extractive value, and 0.89±0.01 g/ml specific gravity extract. The total plate and yeast mold numbers were 15x103 CFU/g and 92 x 10 CFU/g, respectively. The results of metal contamination showed Pb 1.05 ± 0.15 mg/kg and Cd 0.14 mg/kg. The phytochemical evaluation revealed the presence of tannins (69.02%), flavonoids (27.63%), alkaloids (14.18%), saponins (2.12%), and steroids (1.06%). ACE inhibitory activity was tested and obtained at 38.50±1.41 µg/mL for TLE and 9.44±0.58 µg/mL for captopril. Based on the research results, TLE qualifies as a standardized extract and can be used as a reference for developing herbal medicines. Tamoenju leaves extract is quite high as a natural ACE inhibitor and has the potential as an antihypertensive.