The influence of spatial inhomogeneity of short-range exchange on the formation of long- range ferrimagnetic order in dilute spinels is investigated. The objects of investigation are two types of polycrystalline samples of Li0.5Fe1.1Ga1.4O4 differing in the extent of heterogeneity in the distribution of magnetic (Fe3+) and nonmagnetic (Ga3+) ions in the lattice. The heterogeneity was created by using two regimes of thermal treatment, i.e., slow cooling (S) and quenching (Q) of samples from 1550 to 300 K. The results of analysis of magnetization isotherms σT(H) at T=4.2 K, (77–300) K, H⩽16 kOe and temperature dependences of initial susceptibility χ0(T) show that the long-range ferrimagnetic order near the multicritical point (x0=1.5) of the x–T phase diagram is stable to variations of the degree of spatial heterogeneity of the exchange.