This thesis analyzes precision medicine from an ethical and political perspective, especially in terms of distributive justice: it is aimed at investigating the kinds of benefits that can be produced after precision medicine, and the possible distributions of those benefits, by considering the consequent impact of precision medicine on social and health equity. Precision medicine is considered as a social construct subjected to different interpretations, and it is analyzed by mainly referring to two major case studies: the Precision Medicine Initiative in the US, and the 100,000 Genomes Project in the UK. The analysis focuses on the promises of precision medicine, as expressed in the discourses of the two projects, compared with the expectations and the concerns, as expressed in published comments and in fieldwork interviews with relevant stakeholders. The analysis investigated the scope of precision medicine with respect to public health, the inclusiveness of precision medicine, and the democratizing capacities. It emerged that there are different versions of precision medicine, which encompass different scopes and possibly produce different kinds of benefits. In particular, one version, by also including in its scope the social determinants of health, is argued to have the ‘societal potential’ to inform socio-political interventions to promote social equity and, in return, health equity. It is argued that, although the benefits directly deriving from precision medicine - tailored biomedical treatments and information supposed to empower individuals - risk to totally exclude socio-economically disadvantaged groups, thus preventing any solidarity-based participation, on the other hand, the implementation of the ‘social potential’ would foster the public good and a solidarity-based medicine, to the advantage of everybody. Some challenges for the actualization of this ‘societal potential’ are identified and discussed. The aim of this thesis is to contribute to overcoming those challenges by promoting the dialogue and the alignment between medical innovation and socio-political reforms.