Generalized gradient approximation (GGA) computations based on the first-principles density functional theory (DFT) are executed to gain insight into the structural stability and physical properties of the 3d-transition-metalbased praseodymium series of perovskite compounds PrTO$_3$. Correspondingly, to investigate the effect of on-site Coulomb repulsion energy, the exchange-correlation version of GGA is implemented via utilizing the (GGA+U) functional.The computed ground state energies ($E_0$) and equilibrium structural parameters of the varied T-site [T = Sc, Ti, V, Cr, Mn, Fe, Co] in the unit cell of PrTO$_3$ reveal a cubic symmetry (Pm-3m) in all compounds, in a good match with the fewexisting DFT and experimental literature. Besides, the computed spin-polarized band structures and partial and total density of states (DOS) within GGA predict a half-metallic (HM) behaviour for [T = Sc] perovskite and a metallic naturefor the rest [T = Ti, V, Cr, Mn, Fe, Co]. The analysis of E0 results, DOSs and spin magnetic moments indicates that all perovskites PrTO$_3$ are stable in a ferromagnetic (FM) phase via the double exchange interaction T$^{3+}$–O$^{2-}$–T$^{4+}$. PrTO$_3$ show FM order with fractional values of their total spin magnetic moment per unit cell ($M_{PrTO{_3}}$ ), except [T = Sc] perovskite that gives integer value ($M_{PrScO{_3}}$ ${\approx}$ 2.0 ${\mu}_B$) with HM-FM property. Conversely, it is found that PrTO$_3$ exhibit HM-FM properties when [T = Sc, V, Cr, Mn, Fe] plus GGA?U is applied. Due to the cation–anion hybridizations, Pr$^{3+}$–O$^{2–}$ and T$^{3+}$–O$^{2–}$, both Pr$^{3+}$ and T$^{3+}$ ions contribute to the largest part of $M_{PrTO{_3}}$ with minor effects coming from O$^{2–}$ ions and interstitials. Furthermore, the three-dimensional and two-dimensional electronic charge density plots of PrTO$_3$ along the (110) plane confirm strong ionic nature along the Pr$^{3+}$–O$^{2–}$ bonds, whereas the other O$^{2–}$–T$^{3+}$–O$^{2–}$ bondshave strong covalent character.