Cyclic voltammetry and controlled-potential electrolysis have been employed to investigate and characterize the catalytic reductions of 2-bromo- and 2-indoethanol by cobalt(I) cyclam and nickel(I) cyclam, electrogenerated at glassy carbon cathodes in dimethylformamide containing tetramethylammonium tetrafluoroborate. For bulk electrolyses, the principal product is ethylene oxide. along with ethanol, ethylene, and a trace of ethane. For a system originally containing 10 mM 2-bromoethanol anti 4 mM cobalt(II), cyclam. ethylene oxide is formed in 93% yield, but the yield falls to 44% when the initial concentrations of substrate and catalyst precursor are 50 and 1 mh?, respectively. When electrogenerated cobalt(I) cyclam is employed to reduce 2-iodoethanol catalytically and when nickel(I) cyclam is used as a catalyst for the reductions of 2-bromo- and 2-iodoethanol, the maximal yield of ethylene oxide ranges from 44 to 56%.