Here we have studied the selectivity and permeation of recombinant T-type Ca²⁺-channel a1 subunits (Ca_v3.1, Ca_v3.2 and Ca_v3.3). All three subunits showed nearly equal permeability to divalent cations (P_Ca~P_Ba~P_Sr) measured based on the reversal potential changes. Nevertheless, they clearly differed in the macroscopic conductance (for Ca_v3.1:G_Sr>G_Ca>G_Ba, whilst for Ca_v3.2 and Ca_v3.3:G_Ba~G_Sr>G_Ca) and in the binding affinity for these ions (KD-s for Ca²⁺, Ba²⁺ and Sr²⁺ currents saturation through Ca_v3.1 ranged from 1.5 to 5 mM, through Ca_v3.2 ~1 mM and Ca_v3.3 ~0.5 mM). Ca_v3.1 preserved significant Na⁺ permeability even in the presence of up to 10 mM extracellular Ca²⁺, whilst Na⁺ permeation through Ca_v3.2 and Ca_v3.3 diminished at around 1 mM Ca²⁺. Also, in the absence of extracellular Ca²⁺ sizable TEA⁺ (d[cong]8A ^o) carried currents could be observed for all of the subunits tested. Overall we conclude that just as L-type channels, all three Ca_v3 a1 subunits form a wide, multi-ion pore which selects divalent ions by affinity. However, unlike L-type channels they bind divalents much weaker and therefore are unable to exquisitely discriminate between Ca²⁺ and Na⁺. Despite operating on apparently similar mechanisms to deliver ions through the pore, various T-type channels are characterized by slightly different pore properties. In addition, the magnitude of T-currents can be modulated via differential affects of permeating ions on open channel probability.