Introduction. Hanoi is the capital of the Socialist Republic of Vietnam. Hanoi grows according to the following pattern: its central district has several satellites (5 cities) that are accessible by transport systems such as railways, motorways, waterways, etc. Air quality gets worse due to the growing number of urban residents, their personal vehicles, industrial development and other sources of emissions, and each of these factors has a great impact on human health and the state of the environment. Materials and methods. This study uses PM2.5 data generated by two automatic air monitoring stations located in the northern centre for environmental monitoring of the Environmental Protection Agency of Vietnam and the US Embassy in Vietnam. Methods of statistical assessment and analysis were applied to evaluate the difference in PM2.5 dust concentration at different stages of urban development. Results. The problem of PM2.5 pollution in Vietnam is particularly relevant, because it threatens public health. In residential areas located in urban neighborhoods notorious for heavy traffic and industrial enterprises, pollution levels still exceed admissible QCVN limits. On the contrary, air pollution is lower in suburban residential areas. Conclusions. The paper discusses the consequences of environmental pollution, caused by PM2.5 fine dust as a result of urbanization in Hanoi, and analyses urban planning solutions aimed at pollution reduction.