Aim: To assess the effect of various socio-demographic in addition to oral hygiene variables on the oral hygiene and periodontal status. Methods: A combination of multi stage and cluster sampling procedure was followed to collect a representative population of 831, 12 year-old schoolchildren of Udiapur district. Oral Hygiene Index -Simplified (OHI-S) and Community Periodontal Index (CPI) were used to evaluate oral hygiene and periodontal status respectively. Along with the clinical examination, each subject was interviewed to collect the socio-demographic information and oral hygiene practices. Results: The overall mean OHI-S was 1.42 and debris component of the oral hygiene index was dominant. Unpaired 't' test showed significantly higher DI-S (p = 0.0001) and OHI-S (p = 0.007) among boys than girls. The overall prevalence of periodontal disease was 89.9% and gingival bleeding was widespread. Chi square test demonstrated significant differences (p = 0.0001) with 14.6% urban children having healthy periodontium in comparison to 5.6% rural residents. Oral hygiene scores were dependent on the father's occupation (p = 0.046), father's (p = 0.002) and mother's level of education (p = 0.0001). Conclusions: Oral hygiene status was poor, more among boys with debris contributing a major part for oral hygiene index. Periodontal status was poor with bleeding being most prevalent indicator. The multivariate analysis of oral hygiene status confirmed the existence of socio-behavioural determinants for oral hygiene.