Specimens of 18 Ni 1800 MPa (M250) grade maraging steel were charged with different quantities of hydrogen by an electrochemical method. The tensile properties and fracture characteristics have been correlated with the quantity of hydrogen picked up by the material. A drastic decrease in ultimate tensile strength from 1768 M Pa to 750 M Pa, elongation from 6% to less than 2%, and reduction in area from 55% to less than 5%, were observed as the hydrogen content of the steel increased from less than 2 p.p.m. to 7 p.p.m. However, hydrogen does not affect the hardness of the steel. The effect of baking at different temperatures on hydrogen embrittlement was also studied. A change in fractographic features from ductile dimples to mixed mode, intergranular separation and transgranular cleavage was observed as the amount of absorbed hydrogen increased.