  A mixed graph is said to be integral if all the eigenvalues of its Hermitian
adjacency matrix are integer. Let $\Gamma$ be an abelian group. The
\textit{mixed Cayley graph} $Cay(\Gamma,S)$ is a mixed graph on the vertex set
$\Gamma$ and edge set $\{ (a,b): b-a\in S \}$, where $0\not\in S$. We
characterize integral mixed Cayley graph $Cay(\Gamma,S)$ over abelian group in
terms of its symbol set $S$.
