The properties of lattice structures made of titanium alloy Ti-6Al-4V, manufactured using powder bed fusion have been studied in three different states: as-built , after chemical-thermal treatment by ion nitriding and after annealing. The relative porosity of the samples was 50, 60, 70 and 80%. It has been established that ion nitriding of lattice structures leads to the formation of a several tens of micrometers thick nitrided layer on the surface. It was revealed that nitrogen saturation of the surface layers does not have a significant effect on the basic mechanical properties during compression for samples with a of porosity of 50, 60, 70%, however, it leads to a more than 20% increase in the surface hardness of struts. It has been established that annealing at a temperature of 720 °C leads to the decomposition of the initial martensitic α'-phase and the formation of a two-phase (α+β) structure and to the relief of residual stresses.