Microstructure and phase composition of a high chromium oxide dispersion strengthened (ODS) steel Fe-13.5% Cr-2% W-0.3% Y 2 O 3 without a titanium additive, as well as alloyed with 0.2, 0.3, and 0.4 wt % Ti, has been studied using transmission electron microscopy. A comparison of the nanoscale state of the steels under investigation with that of an ODS Eurofer steel alloyed with 0.2 wt % V has been carried out. In all of the states found, a high number density of nanosized oxide inclusions has been observed. Upon an increase of the titanium concentration in the steel Fe-13.5% Cr-2% W-0.3% Y 2 O 3 to 0.3 wt %, the average size of the particles decreases, while their number density grows. In this steel, single nanosized (0.1-0.7 µm) grains or their agglomerates have been found, as well as coarse (6-8 µm) grains.