In vitro drug dissolution is important parameters in pharmaceutical discipline used to be checked the releases of drug product in standard conditions. Telmisartan includes in the classification system BCS class (II). The angiotensin II receptors blocker of Telmisartan freely used for hypertension. The aim of this proposed method was developed and validated to the UV spectrophotometer for the routine quality control check of API containing 40 mg Telmisartan tablets. To investigate the most preferable dissolution method includes dissolution media as 0.1N HCl at 900ml, temperature as 37±0.5°C, rpm as 100, time 60 min. The absorbance maximum of Telmisartan was 296nm. The concentration range of the proposed method was 2-12µg/ml and linearity as r2= 0.999. The result of intraday & interday precision was 0.687% and 0.460% RSD respectively. The result of the percentage recoveries was 98.25%, 100.05%, and 99.75%. The effective dissolution method was developed and validated by UV spectrophotometer which used to be more applicable in various pharmaceutical industries.