thua nao is an indigenous fermented soybean of Northern Thailand. The product can be consumed directly or often used as major ingredient in several local dishes. Similar products include Japanese natto, Indian kinema and Nigerian dawadawa. Such fermented foods are commonly known as alkali fermented soybeans due to bacterial proteolytic activity during the fermentation. Interestingly, these are all household fermentations caused by mixed starter culture of bacilli (except natto which is commercialised and produced by a pure starter culture). In this present study, we aim to summarise the scientific basis of Thai thua nao including fermentation process, microbes involved and nutritive data.