<p>Despite longstanding immunization programmes in India, substantial gaps in childhood vaccination persist across socioeconomic, regional, and demographic groups. This study examines the associations of household living standards, child health, maternal characteristics, and socio-demographic factors with childhood immunization using unit-level data for 39,338 children aged 12–23 months from the National Family Health Survey-5 (NFHS-5). All analyses incorporated sampling weights and primary sampling unit-clustered standard errors to account for the survey’s stratified, multistage sampling design. Composite indices of household living standards and child health were constructed using multiple correspondence analysis and included as key predictors. Survey-weighted logistic regression and LASSO logistic regression models, validated through design-based bootstrap resampling, identified household living standards, maternal education, and institutional delivery as the strongest and most robust predictors of full immunization, including after adjustment for additional controls and state fixed effects. Larger household size, a greater number of children, and female sex were associated with lower immunization coverage. Rural children exhibited higher immunization coverage than their urban counterparts, whereas Hindu children had higher coverage than Muslim children, with no significant difference between Christian and Muslim children. Duration of residence showed a non-monotonic association with immunization, with lifelong residents and non-permanent (“visitor”) households facing higher risks of non-immunization than more recently settled families. These findings support broad-based strategies to improve maternal education, household living standards, and institutional delivery, complemented by targeted interventions for highly mobile households and persistently low-coverage states to reduce immunization inequalities and improve timely vaccine uptake.</p>