Abstract We discuss in general the possibility in quantum field theories of quantum tunneling decays of classically stable, localized, non-trivial field configurations. Such tunneling events would correspond to the decay of metastable particles in the field theory. We illustrate this phenomenon by constructing a model, based on a simple one-space, one-time dimensional field theory, in which such “particle tunneling decays” can actually occur. Using collective coordinate techniques similar to those applied to calculations of nuclear fission, we study the tunneling decay and estimate the lifetimes of the metastable particles. We comment briefly on the role of higher quantum corrections to tunneling and on possible additional examples of these particle tunneling decays.