BackgroundMaternal and child health are important issues for global health policy, and the past three decades have seen a significant progress in maternal and child healthcare worldwide. Immunization is a critical, efficient, and cost-effective public health intervention for newborns. However, studies on these health-promoting indicators in low-income and middle-income countries, especially in sub-Sahara Africa are sparse. We investigated the association between maternal healthcare utilization and complete vaccination in the Republic of Benin.MethodsWe analysed data from the 2018 Benin Demographic and Health Survey (BDHS). Specifically, the children’s recode file was used for the study. The outcome variable used was complete vaccination. Number of antenatal care visits, assistance during delivery, and postnatal check-up visits were the key explanatory variables. Bivariate and multilevel logistic regression analyses were carried out. The results were presented as unadjusted odds ratios (uOR) and adjusted odds ratios (aOR), with their corresponding 95% confidence intervals (CIs) signifying their level of precision. Statistical significance was declared at p < 0.05.ResultsThe prevalence of full immunization coverage in Benin was 85.4%. The likelihood of full immunization was lower among children whose mothers had no antenatal care visits, compared to those whose mothers had 1–3 visits [aOR = 0.11, 95% CI: 0.08–0.15], those who got assistance from Traditional Birth Attendants/other during delivery, compared to those who had assistance from Skilled Birth Attendants/health professionals [aOR = 0.55, 95% CI: 0.40–0.77], and mothers who had no postnatal care check-up visit, compared to those who had postnatal care check-up < 24 h after delivery [aOR = 0.49, 95% CI: 0.36–0.67]. With the covariates, religion, partner’s level of education, parity, wealth quintile, and place of residence also showed significant associations with full immunization.ConclusionThe study has demonstrated strong association between full immunization and antenatal care, skilled attendance at birth, and postnatal care check-up visit. We found that full immunization decreases among women with no antenatal care visits, those who receive assistance from Traditional Birth Attendants during delivery, and those who do not go for postnatal care visits. To help achieve full immunization, it is prudent that the government of Benin collaborates with international organisations such as WHO and UNICEF to provide education to pregnant women on the importance of immunization after delivery. Such education can be embedded in the antenatal care, delivery and postnatal care services offered to pregnant women during pregnancy, delivery, and after delivery.