A Kähler solvmanifold is a connected Kähler manifold
(
M
,
j
,
⟨
,
⟩
)
(M,j,\left \langle , \right \rangle )
admitting a transitive solvable group of automorphisms. In this paper we study the isomorphism classes of Kähler structures
(
j
,
⟨
,
⟩
)
(j,\left \langle , \right \rangle )
turning
M
M
into a Kähler solvmanifold. In the case when
(
M
,
j
,
⟨
,
⟩
)
(M,j,\left \langle , \right \rangle )
is irreducible and simply connected we show that any Kähler structure on
M
M
, having the same group of automorphisms, is isomorphic to
(
j
,
⟨
,
⟩
)
(j,\left \langle , \right \rangle )
.