Background: Oral health is a part of general health and hence, has a direct bearing on the total well-being of individuals. Knowledge of oral health status and treatment needs of populations with different characteristics is important for developing appropriate preventive approaches. Aim: The aim of the study is to determine the relationship between oral hygiene with socioeconomic status among 15 years old school going children of Lucknow city. Materials & Methods: A descriptive cross-sectional study was conducted. The schools were selected by simple random sampling method following the lottery method of selection. Simplified Oral Hygiene Index with Kuppuswamy’s socioeconomic status scale has been used. Results: As socio-economic status decreases; mean OHI-S increases. Comparing the mean OHI-S between different SES groups, ANOVA revealed significantly different OHI-S among the groups (F=38.84, p<0.001). Conclusion: The mean scores of OHI-S revealed a significant relation with socio-economic status. It was reported that as the socioeconomic status decreased, oral hygiene status of the children deteriorated.