A shielded electrical ribbon cable includes conductor sets each including one or more insulated conductors, and a first and second shielding film on opposite sides of the cable. In transverse cross section, cover portions of the shielding films substantially surround each conductor set, and pinched portions of the films form pinched portions of the cable on each side of each conductor set. Dense packing is achieved while maintaining high frequency electrical isolation between conductor sets. When the cable is laid flat, a quantity s/Dmin is in a range from 1.7 to 2, where S is a center- to-center spacing between nearest insulated conductors of two adjacent conductor sets, and Dmin is the lesser of the outer dimensions of such nearest insulated conductors. Alternatively, a first and second conductor set each having only one pair of insulated conductors can satisfy a condition that Σ/σ1 is in a range from 2.5 to 3.