Neutron stars are a unique laboratory for testing matter under extreme conditions. The aim is to understand neutron star observables, such as the mass, typical radii, cooling evolution, magnetic fields or rotation, in terms of a plausible scenario for its interior.Over the last years a particular effort has been invested in studying matter with strange content inside neutron stars. To this end our proposal addresses different aspects of dense matter with strangeness emphasizing the systematic and reliable procedure used. This analysis is done in close connection to back-to-Earth experimental programs.Specifically, the properties of hadrons with strangeness in dense matter will be studied within the framework of effective field theories. Effective field theory is a useful tool for dealing systematically with meson-baryon and baryon-baryon interactions. The effective interactions in matter will be then built by incorporating many-body effects. Once known those interactions, the implications for certain neutron star properties will be discussed, such as the equation of state for strange hadronic matter, the corresponding mass-radius relationship, and non-radial oscillations in the presence of strong magnetic fields within the hadronic scenario as well as for strange quark matter and in an hadronic-quark hybrid phase. The ultimate goal is to offer predictions for neutron star observables keeping under control the theoretical uncertainties.