Dimer fatty acid (DA)-based polyol (DAP) was synthesized successfully by DA and glycerol via esterification. The chemical structure of DAP was characterized by nuclear magnetic resonance, Fourier transform infrared, gel permeation chromatography as well as acid and hydroxyl values. Then it was used to substitute petrochemical polyol and prepare rigid polyurethane foams (RPUFs). The aim of this study was to evaluate the influence of DAP polyol on physical, mechanical and thermal stability properties of RPUFs. The results showed that the apparent density and compressive strength decreased and thermal conductivity remained the same with introducing of DAP. The incorporation of vegetable polyol DAP improved water-resisting property of RPUF. Water contact angle increased from 120.5 degrees to 132.0 degrees; meanwhile, water absorption decreased from 4.5 to 1.8% with increase in DAP content. The thermogravimetric analysis results indicated that the thermal stability of RPUF improved by incorporating DAPs. It indicated that as a bio-resource polyol, DAP can substitute partial petrochemical polyol to prepare RPUF with a good comprehensive performance.Graphical abstractDimer fatty acid (DA) derived from renewable and natural oleic acids was used to synthesized polyester polyol with glycerol named as DAP. Then it was used to substitute petrochemical polyol and prepare rigid polyurethane foams (RPUFs). The obtained RPUF showed better thermal stability and lower water absorption than commercial polyol (GR4110). The excellent properties made DAP a potential candidate of petroleum-based polyols [GRAPHICS] .