Titanium alloys are widely utilized for structural applications in aerospace, automotive, military, sport equipment and chemical engineering due to their high specific strength, excellent corrosion resistance and stable moderate temperature properties. In this work, samples from titanium alloys exposed to laboratory air at 625°C for 1000 h, which resulted in the formation of an oxide scale and a layer with higher oxygen concentration. The depth of oxygen-enriched layer after annealing was estimated by four methods: metallographic examination, fractography, hardness testing and XRD analysis. This paper summarizes an effort to estimate depth of oxygen-enriched layer in titanium alloys after elevated temperature exposure.