An imide dicarboxylic acid was prepared from 1,6-diaminohexane and trimellitic anhydride and esterified with ethanol. This imide monomer was polycondensed with three different poly(tetramethylene oxide) diols (PTMO-650, PTMO-1000 and PTMO-2000) and with an excess of 1,4-dihydroxybutane. When PTMO-1000 was used, and even more when PTMO-2000 was used, a partial macrophase separation occurred at the end of the polycondensation process. The resulting poly(ether-ester-imide)s (PEEIs) were characterized by IR and 1H NMR spectroscopy, by viscosity and DSC measurements. Compared to thermoplastic elastomers based on poly(butylene terephthalate) these PEEIs crystallize slowly. Selected PEEIs were also characterized by dynamic melt rheology, by dynamic mechanical thermoanalysis, by stress–strain and by hysteresis measurements.