  The origin of neutrino masses and the nature of dark matter are two of the
most pressing open questions of the modern astro-particle physics. We consider
here the possibility that these two problems are related, and review some
theoretical scenarios which offer common solutions. A simple possibility is
that the dark matter particle emerges in minimal realizations of the see-saw
mechanism, like in the majoron and sterile neutrino scenarios. We present the
theoretical motivation for both models and discuss their phenomenology,
confronting the predictions of these scenarios with cosmological and
astrophysical observations. Finally, we discuss the possibility that the
stability of dark matter originates from a flavour symmetry of the leptonic
sector. We review a proposal based on an A_4 flavour symmetry.
