Background and AimsBangladesh did not have enough evidence on the current estimates and trend in inequities in the under‐five mortality rate (U5MR). There is also a shortage of evidence on trends and inequalities in healthcare‐seeking for pneumonia among under‐five children (U5C) in Bangladesh. Hence, this study investigated the inequalities in U5MR and health care seeking for pneumonia in U5C through socioeconomic and geographic disparities in Bangladesh between 2007 and 2017.MethodsData from 2007, 2011, 2014, and 2017 Bangladesh Demographic and Health surveys were analyzed using the Health Equity Assessment Toolkit (HEAT) software by World Health Organization (WHO). The data on U5MR and healthcare‐seeking for pneumonia were first disaggregated into five equity dimensions: wealth status, education, child sex, place of residence, and administrative divisions. Second, using summary metrics such as difference (D), population attributable risk (PAR), ratio (R), and population attributable fraction (PAF), inequalities were assessed.ResultsThe U5MR declined from 73.9 deaths per 1000 live births in 2007 to 48.6 deaths in 2017, while the prevalence of healthcare‐seeking for pneumonia in U5C fluctuated over time (34.6% in 2007, 35.4% in 2011, 42.0% in 2014, and 39.8% in 2017). Profound socioeconomic and geographic disparities in U5MR and the prevalence of healthcare‐seeking for pneumonia in U5C favored the wealthy, educated, and urban residents. At the same time, the Sylhet division showed the worst situation for U5MR. There were also sex‐related disparities in U5MR (PAR = −4.5, 95% confidence interval: −5.3 to −3.7) with higher risk among male children than females.ConclusionThese results indicate that improving disadvantaged women, such as the poor, uneducated, and rural inhabitants, who exhibit disproportionate disparities in U5MR and healthcare‐seeking behavior is important. To reduce childhood mortality, it is essential to improve healthcare‐seeking for pneumonia among U5C. Facilitating women for better education and economic encompasses would help reducing disparity.