Traditionally, Thai foods are prepared daily by housewives in every Thai household. Yet, selling food is a common economic activity in old Siam, as various ingredients, fruits and traditional delicacies were offered at "floating markets" in canals as early as the Ayutthaya Period (1350–1767). Floating market food or canal food has been sold from boats on Thailand's rivers and canals for over two centuries. However, since the early 20th century King Rama V's modernizations caused a shift towards land-based stalls. The street food culture of Southeast Asia was introduced by coolie workers imported from China during the late 19th century and many Thai street foods are derived from or heavily influenced by Chinese cuisine.
There is scarcely a Thai dish that is not sold by a street vendor or at a market somewhere in Thailand. The foods that are made to order, tend to be dishes that can be quickly prepared: usually quick stir fries with rice. Noodles are a popular street food item as they are mainly eaten as a single dish. Chinese-style noodle soups, fried noodles, and fermented Thai rice noodles (khanom chin), served with a choice of different Thai curries, are popular.