Southeast Asia is one of the world biodiversity hotspot. The study of diatoms in this area began over a hundred years ago. However, research on taxa inhabiting terrestrial habitats are scarce. As a result, many species are still waiting to be described. In the present paper, four diatom taxa based on observation in light and scanning electron microscopy are described as new: Hantzschia minima sp. nov., H. tokarczukiana sp. nov., H. malaysiana sp. nov. and H. beksinskii sp. nov. For each species information about an associated diatom flora is provided. An additional note about morphology of co-occurred cosmopolitan H. amphioxys is also discussed.