[en] Highlights: •High radiation tolerance of ${\alpha }_2$ -Ti₃Al is determined by its ordered crystal structure. •Primary damage in Ti₃Al is compared with that in Ti-25at.%Al disordered solid solution. •Notable fraction of high radiation tolerance of Ti₃Al is retained after disordering. •Other PKA energy dissipation mechanisms contribute to radiation tolerance of ${\alpha }_2$-Ti₃Al. - Abstract: A molecular dynamics study of radiation damage created in collision cascades in D0₁₉ Ti₃Al intermetallic compound and a Ti-Al binary disordered solid solution with the same chemical composition is carried out. Collision cascades are initiated by either Al or Ti primary knock-on atoms (PKA) with PKA energy 5 keV $\le E_{PKA}\le$ 20 keV in the two materials at temperature T ranging from 100 K to 900 K. A series of at least 32 different cascades for each ($E_{PKA}$, T) set was simulated in order to imitate an isotropic spatial and random temporal distribution of PKAs, generate representative sampling and obtain statistically reliable quantitative results. The numbers of Frenkel pairs, $〈N_{FP}^{{\alpha }_2}〉$ and $〈N_{FP}^{\alpha }〉$, formed in ${\text{D0}}_{19}$ Ti₃Al intermetallics and Ti-25at.%Al disordered solid solution, respectively, were averaged over collision cascades with the same ($E_{PKA}$, T) and used to quantify the radiation resistance against primary damage formation. It is shown that the relationship $〈N_{FP}^{{\alpha }_2}〉\le 〈N_{FP}^{\alpha }〉$ is satisfied under all simulation conditions, i.e. D0₁₉ ordered crystal structure of Ti₃Al intermetallics is an important feature affecting its radiation tolerance. Nevertheless, a relatively high resistance against the formation of primary radiation defects has been retained even after complete disordering of D0₁₉ Ti₃Al, which points out to the existence of additional mechanisms governing its radiation tolerance.