Although Nepal is a country rich in natural beauty, along with an abundance of natural resources, the children of this diverse nation still face several serious health issues arising from their own environment (water pollution, air pollution, chemical pollution, solid waste issues and drainage issues). Nepal also ranks as a highly vulnerable country to the adverse impacts of climate change. Children are more vulnerable to various infections for immunological, physiological and social reasons. Their inherent immunity diminishes within months after birth. There are risk factors for the development of various diseases, e.g. unsafe drinking water and lack of sanitation, which contribute to diarrheal diseases, trachoma, hookworm and amoebic dysentery; another risk factor is indoor air pollution. The infant mortality rate (IMR) is higher in rural areas with 55 per 1000 live births, compared to urban areas with 38 per 1000 live births. Likewise, the under-5-year-old mortality rate (MR) in rural areas is 64 and that in urban areas is 45 per 1000 live births. Around 12% of the population suffer from chronic respiratory diseases, according to a recent study exploring the situation in Kathmandu. Pneumonia is a leading cause of mortality among children under 5 years of age in Nepalese hospitals. Children under 5 are more prone to the ill effects of polluted environments because of their less well-developed immune system. In addition, the school environment is not sufficiently healthy due to the distribution of unsafe drinking water and poor sanitation supply systems. In Nepal, mainly in the 20 Terai districts, arsenic contamination of groundwater is a public health problem. Underground water is used as drinking water in those areas, but without purification – the estimate is that around 0.5 million people live at the risk of arsenic poisoning. Within a span of 200 km from north to south, the climate of Nepal varies from arctic to tropical. The annual average air pollution concentration is 5 times above the World Health Organization (WHO) air quality guidelines, which poses a serious health risk to hundreds of thousands of Nepalese people: 133 out of 1,000,000 deaths each year are related to air pollution. Dramatically, Kathmandu city is a silent killer to walk around due to air pollution, and its air quality is ranked as the worst out of 180 countries, according to the 2018 Environmental Performance Index. However, insufficient studies have been conducted to explore children’s environmental health issues. It is therefore essential to carry out more scientific studies to explore the issues of children’s environmental health as environmental health problems in children are serious in the Nepalese context.