The purpose of this paper is to discuss the characteristics of coaxial cable which are of major importance in CATV system performance. We shall attempt to accomplish this by showing how the cable affects system design and customer picture quality. We also shall attempt to show the substantial improvements which have been made in cable design and manufacture in the past 15 years, and to discuss what remains to achieve the optimum cable design of the future. As a result of this discussion we hope to have underlined those cable characteristics most critical to system performance.