Abstract: An electrical cable is described comprising a threadlike conductor, an insulator and a sheat. The cable according to the invention is characterized in that the outer surface of said sheat has some portions standing out with respect to an average line and portions which are below it. In particular, the portions standing out with respect to an average line and the portions which are below it define a plurality of longitudinal grooves. the cable according to the invention has many advantages over conventional cables such as a greater heat-loss capability, a greater flexibility, smaller overall dimensions and lower laying friction of the cable itself.