Background: Nitrate is a renowned pollutant in water and soil. Nitrate is used mostly as a nitrogen fertilizer. When nitrate seeps into the ground it can get into drinking water. Traces of nitrite and nitrate in drinking water may lead to methemoglobinemia in infants and with long term exposure is a possible cancer risk. Concentration of nitrate above 45 mg/L as nitrate and 10 mg/L as nitrate-nitrogen is unsuitable for domestic use according to BIS (Bureau of Indian Standards). Methods: Nitrates are mainly determined by the spectrometric, colorimetric and ion chromatography methods. Majority of these methods are slow measurement, laborious and require the use of toxic and expensive reagents. In this study, ultraviolet spectrophotometric method is utilized for detection of nitrate optically with no chemical reagents. This method is simple and cost-effective. Nitrate and nitrite concentrations were analysed at various wavelengths (220 to 370 nm) and 240 nm was found to be efficient for detecting both nitrate and nitrite. Result: Various groundwater samples in and around Karunya Campus and nearby residential places, Coimbatore, Tamil Nadu were analysed and compared with one borewell water sample from West Bengal State which was prone to contaminated ground water. The results show that all the ground water samples have nitrate and nitrite concentration within the permissible limit but the sample from West Bengal has higher concentration compared to Coimbatore samples.