Single crystals of Pr2Fe4-xCoxSb5 (1 < x < 2.5) were grown from a Bi flux and characterized by X-ray diffraction. The compounds adopt the La2Fe4Sb5 structure type (I4/mmm). The structure of Pr2Fe4-xCoxSb5 (1 < x < 2.5) contains a network of transition metals forming isosceles triangles. The x similar to 1 analogue is metallic and exhibits a magnetic transition at T-1 approximate to 25 K. The magnetic moment obtained from the Curie-Weiss fit is 11.49(4) mu(B), which is larger than the spin-only Pr3+ moment. The x similar to 2 analogue orders magnetically at T-1 approximate to 80 and T-2 approximate to 45 K. This is the first case of the substitution of Co into the La2Fe4Sb5 structure type, evidenced by the increased concentration of dopant with decreased lattice parameters coupled with a change in the transition temperature with a change in the cobalt concentration. The added complexity in the magnetic behavior of the x similar to 1 and 2 analogues indicates that the increased concentration of Co invokes an additional magnetic contribution of the transition metal in the sublattice. Furthermore, X-ray photoelectron spectroscopy measurements support the change in the oxidation states of transition metals with increasing cobalt concentration.