BackgroundParental burnout has become increasingly common, which can lead to a range of adverse outcomes. Postnatal mothers are vulnerable and mothers with high postpartum depression scores may be more prone to parental burnout. This study aims to investigate the association between postnatal depressive symptoms and parental burnout at both the population and individual levels.MethodsThis study comprised a cross-sectional study design and participants were recruited using convenience sampling. A total of 560 postnatal mothers answered a questionnaire on their general information, postnatal depressive symptoms and parental burnout. Multiple linear regression and binary logistic regression analysis were used to examine the association between postnatal depressive symptoms and parental burnout. Furthermore, latent class analysis was used to identify subtypes of parental burnout. Finally, binary logistic regression was used to examine the differences in postnatal depressive symptoms between latent classes comprising parental burnout.ResultsThe prevalence of burnout was approximately 10%. At the population level, postnatal depressive symptoms were positively associated with parental burnout (allP< 0.05). At the individual level, two latent classes were identified (i.e., “low parental burnout class” and “high parental burnout class”). Moreover, mothers with postnatal depressive symptoms were more likely to be associated with high parental burnout (PB) class than the low parental burnout class (OR= 1.12, 95% CI:1.03 to 1.23).ConclusionThis study found a positive relationship between postnatal depressive symptoms and parental burnout. It provided evidence for developing depression-targeted programs for parental burnout, which could bring great benefits for both mothers and infants.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12888-023-04853-2.