BACKGROUND– Dental caries is unique not only in terms of the pathological mechanism; other aspects, social and economical, are also worthy of note.1 The concentration of nitrate in saliva varies according to dietary nitrate intake, the activity of bacterial nitrate reductase, salivary flow rate, and endogenous production of nitrate.2 AIM– To comparatively evaluate the salivary nitric oxide levels in ECC and non–ECC children. MATERIAL AND METHODS– 100 children were included in the study, group I was of 50 non–ECC children and group II was of 50 children with ECC. Nitric oxide was estimation done by using Griess Reagent. RESULT– The nitric oxide levels in Group I was 54.07±15.68 and Group II was 34.84± 10.79. CONCLUSION– Based on the present study and available literature it can be concluded that nitric oxide is decreased in the saliva of ECC patient