Fil: Bordas, Pol. Universidad de Barcelona; EspañaFil: Paredes, Josep M. Universidad de Barcelona; España.Fil: Paredes, Josep M. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bosch Ramon, Valentí. Max-Planck Institut für Kernphysik; AlemaniaFil: Orellana, Mariana D. Comisión de Investigaciones Científicas; ArgentinaFil: Orellana, Mariana D. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Orellana, Mariana D. Instituto Argentino de Radioastronomía; ArgentinatrueWe present a model to estimate the synchrotron radio emission generated in microquasar (MQ) jets due to secondary pairs created via decay of charged pions produced in proton-proton collisions between stellar wind ions and jet relativistic protons. The synchrotron radiation produced by secondary electrons/positrons is computed using consistently derived particle energy distributions. Energy losses due to synchrotron and inverse Compton (IC) processes, and adiabatic expansion, are taken into account. The space parameter for the model is explored and the corresponding spectral energy distributions (SEDs) are presented. We conclude that secondary leptonic emission represents a significant though hardly dominant contribution to the total radio emission in MQs, with observational consequences that can be used to test some still unknown processes occurring in these objects as well as the nature of the matter outflowing in their jets.