Solid solutions based on ZrB2 possess improved structural properties as compared to single borides due to lattice distortion and strengthening by nano-inclusions; however, the effect of additional transition metals on the oxidation behavior is still unclear. Pore-free (Zr,Ti,Me)B2 ternary solid solutions, with Me = Hf, V, Nb or Cr, were oxidized at 1500 °C for 5 min in a bottom-up loading furnace to study the microstructural evolution and understand the oxidation sequence. All ternary borides formed a thinner oxide scale than the reference (Zr,Ti)B2 matrix. Cr provoked relevant bubbling in the sub-scale that compromised the oxide structural stability, Nb and V formed liquid mixed oxides that partially prevented oxygen penetration, whereas Hf showed an intermediate behavior, according to thickness measurements. Based on the minimization of Gibbs free energy for the oxidation reaction, a metal consumption sequence was delineated to suggest a favorable mixture that could provide protection over a broad temperature range. Graphical abstract