INRIM is the NMI of Italy. The Thermometry Research Program of INRiM has conducted several state-of-the-art primary thermometry experiments with different methods, including AGT and RIGT. Notable recent achievements of INRiM in this field comprise the determination, by AGT of the Boltzmann constant with 1.1 ppm uncertainty and the determination of thermodynamic temperature from 13 K to 430 K. INRIM has given significant contributions to a number of Imera+, EMRP and EMPIR projects dedicated to the advancement of temperature and humidity metrology. The apparatus, devices, artefacts, instrumentation and facilities which are necessary to the realization of accurate speed of sound and refractive index measurements in gases for primary thermometry are available at INRIM.