ObjectivesThis study aimed to investigate whether childhood dental caries was associated with self‐reported general health in midlife.MethodsWe used data on childhood oral health (caries experience) and adult self‐reported general health from two New Zealand longitudinal birth cohorts, the Dunedin Multidisciplinary Health and Development Study (n = 922 and n = 931 at ages 5 and 45 years, respectively), and the Christchurch Health and Development Study (n = 1048 and n = 904 at ages 5 and 40 years, respectively). We used generalized estimating equations to examine associations between age‐5 dental caries and self‐rated general health and the number of self‐reported physical health conditions at ages 45/40 (diagnosed by a doctor or health professional, n = 14 conditions among both cohorts). Covariates included known risk factors for poor health (SES, IQ, perinatal complications), and personality style, which is known to affect subjective health ratings.ResultsIncidence rate ratios for ‘Excellent’ self‐rated health were lower among those who had high experience of dental caries as children than those who had not in both, the Dunedin (IRR, 0.76; 95% CI, 0.50, 1.14) and Christchurch studies (IRR, 0.69; 95% CI, 0.47, 1.00). Childhood dental caries was not associated with the number of self‐reported physical health conditions in midlife, in either cohort. Dunedin Study members who at age 5 were not caries‐free or whose parents rated their own or their child’s oral health as poor were less likely to report ‘Excellent’ self‐rated general health at age 45 than those who were caries‐free and whose parents did not give a ‘poor’ rating (IRR, 0.69; 95% CI, 0.49, 0.97).ConclusionsFive‐year‐olds with greater caries experience were more likely to have poorer self‐rated general health by midlife. Beyond this longitudinal association, future research should examine whether childhood dental caries is associated with objective/biological markers of physical health and whether it may have utility as an early indicator for poor general health in adulthood.