Public health services remain weak in Mondulkiri due to the lack of infrastructure connecting remote villages. This province contains a high level of biodiversity, including medicinal plants that people use to treat diseases and ailments, but deforestation now threatens these natural resources. This paper analyses the importance of medicinal plants and their different therapeutic uses in two villages in Mondulkiri. Then, we study the economic value of these plants through analysing household expenditure on health care. The results show that the use of medicinal plants helps villagers to significantly reduce the costs incurred from stomach aches, post partum pains, diarrhoea and colds. By restoring physical health and economic activity at a lower cost than synthetic drugs or other alternatives, medicinal plants help vulnerable people to alleviate or avoid poverty.