We study the Northcott and Bogomolov property for special values of Dedekind \(\zeta \) -functions at real values \(\sigma \in \mathbbm {R}\) . We prove, in particular, that the Bogomolov property is not satisfied when \(\sigma \ge \frac{1}{2}\) . If \(\sigma > 1\) , we produce certain families of number fields having arbitrarily large degrees, whose Dedekind \(\zeta \) -functions \(\zeta _K(s)\) attain arbitrarily small values at \(s = \sigma \) . On the other hand, if \(\frac{1}{2} \le \sigma \le 1\) , we construct suitable families of quadratic number fields, employing either Soundararajan’s resonance method, which works when \(\frac{1}{2} \le \sigma < 1\) , or results on random Euler products by Granville and Soundararajan, and by Lamzouri, which work when \(\frac{1}{2} < \sigma \le 1\) . We complete the study by proving that the Dedekind \(\zeta \) function together with the degree satisfies the Northcott property for every complex \(s\in {\mathbbm {C}}\) such that \(\textrm{Re}(s) <0\) , generalizing previous work of Généreux and Lalín.