This work focuses on the fatigue behaviour of notched Ti-6Al-4V titanium alloy in inert environment. V-notched flat samples were cycled under axial fatigue (R = 0.1) under inert conditions by immersion in paraffin oil. A step-loading technique was used to determine the fatigue limit at the complete fracture for a constant fatigue life of 2×105 load cycles. The results were compared with previous data obtained with tests carried out in air and 3.5 wt.% NaCl solution. Fracture surfaces were examined under stereoscopic microscope.