In the present study, biobased furan dicarboxylate polyesters have been prepared using 2,5-furandicarboxylic acid (FDCA) and diols with high number of methylene groups (long chain diols), namely 8, 10 and 12, which are named as poly(octylene 2,5-furanoate) (POF), poly(decylene 2,5-furanoate) (PDeF) and poly(dodecylene 2,5-furanoate) (PDoF), respectively. Semi-crystalline polyesters with number average molecular weight ranging from 34000 to 39000 g/mol have been prepared and their chemical structure was proved by 1H NMR spectroscopy. A systematic investigation of the thermal stability and decomposition kinetics of these polyesters was performed, using thermogravimetric analysis (TGA) and pyrolysis-gas chromatography/mass spectroscopy (Py-GC/MS). From TGA curves it was found that all polyesters have high thermal stability since their decomposition starts around 340 °C and completes near 500 °C. The decomposition mechanism of the studied polyesters was also studied with pyrolysis-gas chromatography/mass spectroscopy (Py-GC/MS). From the identified decomposition products after pyrolysis at 350 and 450 °C, it was found that the decomposition of these polyesters is taking place mainly via β-hydrogen bond scission and in lower extent with homolytic >C-C< radical decomposition and with α-hydrogen scission.