X(3872): Hadronic molecules in effective field theory

We consider the implications from the possibility that the recently observed state X(3872) is a meson-antimeson molecule. We write an effective Lagrangian consistent with the heavy-quark and chiral symmetries needed to describe X(3872). We explore the consequences of the assumption that X(3872) is a molecular bound state of D∗0 and D¯0 mesons for the existence of bound states in the D0D¯0 and D∗0D¯∗0 channels.