Particulate matter in up to13 size fractions was collected in up to 72 hour samples from a 5th floor window in Lak Si, Bangkok, Thailand; and from Pollution Control Department (PCD) sites in Ayutthaya, Bang Phli and Chok Chai, in or near Bangkok using a Dekati Electrical Low Pressure Impactor Classic (ELPI). Samples were weighed and analysed for concentrations of the following elements: Mg, Al, V, Cr, Mn, Fe, Co, Ni, Cu. Zn, As, Se, Mo, Cd, Sb, Ba and Pb. The data covered three seasons in Bangkok, hot, cool and rainy, from February 2018 until December 2018. Measurements were taken by the staff of the Toxicology group in the Chulabhorn Research Institute, Thailand and the Atmospheric Chemistry Research Group in the University of Bristol, UK, with the assistance of the PCD, Bangkok, at their sites.