The electrical conductivity of poly(ethylene oxide)-MAg4I5 (M = Li, K, Rb) compounds has been measured for M : O ratios between 0.1 and 1.0. For P(EO)1KAg4I5 the conductivity is 2 × 10−3 ω−1 cm−1 at room temperature and the activation energy is 0.16 eV.