Hydrogen embrittlement of precipitation hardened Ni- alloys is receiving increasing attention by the oil and gas industry. Several component failures have been imputed to this phenomenon. In this context an R&D test program has been implemented to evaluate the susceptibility to hydrogen embrittlement of the following products: 935 (UNS N09935) alloy with 110 ksi Minimum Yield Strength (MYS) 825PH (UNS N09925) alloy with 110 ksi MYS 718 (UNS N07718) alloy with 120 ksi MYS and with 140 ksi MYS 7716 (UNS N07716) alloy with120 ksi MYS and with 140 ksi MYS. These materials were characterized in terms of chemical analysis mechanical properties and microstructure. They were tested for susceptibility to hydrogen embrittlement according to a procedure issued by Total. Both 7716 grades resulted to be highly susceptible to hydrogen embrittlement Both 718 grades 935 and 825PH resulted not susceptible to this phenomenon. Test results are discussed as a function of the material properties. The precision of the test procedure is also assessed.