Pyridine derivatives of tungsten pentacarbonyl have been extensively studied due to their interesting photochemical and photophysical properties. Their electrochemical properties, however, have not received substantial attention as they typically undergo chemically irreversible redox processes, the products of which are difficult to ascertain. This presentation summarizes our work that elucidates a variety of chemical pathways undertaken by electrochemically generated [W(CO)₅(py)]⁺ radical cations. Cyclic voltammetry studies in non-coordinating solvents indicate that the one-electron bulk oxidation (E_a = 1250 mV vs. Ag/AgCl) is coupled to a rapid chemical reaction, resulting in a nearly irreversible anodic peak. The presence of low concentrations of additional pyridine, however, results in rapid ligand substitution the product of which, [W(CO)₄(py)₂]⁺, exhibits a reversible coupled reduction (E_1/2 = 600 mV). This radical cation was also generated by oxidation of the neutral complex W(CO)₄(py)₂ and characterized by infrared spectroelectrochemistry. When generated in the presence of a large excess of pyridine [W(CO)₄(py)₂]⁺ undergoes two reactions: a ligand-induced disproportionation yielding W(CO)₄(py)₂ and [W(CO)₄(py)₃]²⁺, and a second carbonyl substitution, yielding [W(CO)₃(py)₃]⁺. Both reactions are thought to proceed via the nineteen-electron intermediate [W(CO)₄(py)₃]⁺. Electrochemical evidence for these reaction pathways will be presented.