This paper presents a method based on evolution strategies for designing large rural low-voltage (lv) distribution networks. Planning rural lv distribution networks involves radial configuration design, location of medium-voltage/low-voltage substations, and minimum cost. In this work, these goals are considered by taking into account different conductors, voltage drop and conductor capacity constraints, power losses in lines, and deterministic loads. The algorithms developed in this paper are based on evolution strategies (ES) and were implemented on large-scale rural lv distribution networks, but they could also be used in general network optimization.