The market structures of the South Korean cable television industry are amixture of monopoly and duopoly. Using year 2005 data from 77 cabletelevision markets, this paper studies the effect of monopoly on the price ofcable television service. The results of this paper show that monopoly has theeffect of raising the price by 12 to 18 percents and by 17 to 20 percents whenPooled-OLS and fixed-effects estimation method are used, respectively. Wealso perform OLS using a price index weighted by the number of subscribers.The OLS result shows a significant price increase effect of monopoly, which iseven higher than those from the Pooled-OLS and fixed-effects analyses.