Area - 44.615 km2 (17.226 sq mi)
Population - 200,374
Sai Mai was the name of a muban in tambon Khu Khot, Amphoe Lam Luk Ka, Pathum Thani Province. It was transferred to Amphoe Bang Khen and promoted to a subdistrict (Tambon) in 1940. Due to the growth of population in the area, Sai Mai was elevated to a district effective 21 November 1997 to improve the service and administration.
- Wat Amarawanaram
- Sarasas Witaed Saimai School