Experimental data obtained during the characterization of a R744 ejector in low-temperature suction operating conditions. The complete description of the experimental setup and of the R744 cooling unit concept designed to employ the tested ejector, as well as the discussion on the experimental data, are available in: Fabris, F., Pardiñas, Á. Á., Marinetti, S., Rossetti, A., Hafner, A., Minetto, S. (2023). A novel R744 multi-temperature cycle for refrigerated transport applications with low-temperature ejector: experimental ejector characterization and thermodynamic cycle assessment. International Journal of Refrigeration.