Abstract This paper presents a methodology aimed at assisting irrigation district managers in the optimal rehabilitation of pressurized irrigation networks. The methodology uses a multi-objective approach and finds optimal trade-off between investments and long term operational costs. The approach is based on two steps: 1—application of two alternative optimization algorithms to determine optimal trade-offs between installation costs and pump power absorption; 2—post-processing of the optimal solutions in terms of long term costs under various possible scenarios generated featuring various values of the useful construction life and of the capital recovery factor. Applications were carried out on a real case study, considering a pre-fixed electricity tariff and the on-demand operation of the network. After analyzing the results, the most cost-effective solution, with a redesign cost of 205,627 €; and overall cost varying from 6,019,447 €; to 11,498,053 €; according to the scenarios considered, was selected.