Every associative K-algebra A is with respect to the multiplication a • b := ab − ba for all a, b ∈ A a Lie-Algebra A • , also known as the Lie-Algebra associated with A. In [8] S. Siciliano studies Cartan-Subalgebras of A • . These are nilpotent subalgebras C of A • which coincide with the normalizerFor every finite-dimensional associative unitary K-algebra A Siciliano proofs that the Cartan-Subalgebras of A • are exactly the centralizers of the maximal tori of A. Especially, Cartan-Subalgebras of A • are subalgebras of the associative algebra A. A torus is a commutative unitary subalgebra of A for which every element is separable over K. An element is separable if its minimal polynomial is a product of pairwise irreducible separable polynomials of K[t]. For the algebra classes "finite-dimensional central division algebras" and "finite-dimensional soluble algebras" S.Siciliano describes the Cartan-Subalgebras in terms of 'maximal separable subfields' and 'radical complements'.At first we give alternative proves for Sicilianos results concerning these two algebra classes. As an example we compute the Cartan-Subalgebras for soluble group algebras and especially for soluble group algebras related to dihedral groups. After this we describe the Cartan-Subalgebras for finite-dimensional associative division, simple, semi-simple and reduced algebras.As a associative subalgebra we analyze the associative structure of Cartan-Subalgebras. This investigation is closely connected to the question for which finite-dimensional associative unitary algebras its group of units is nilpotent. We close this article by giving a strategy for computing Cartan-Subalgebras for associative algebras with separable radical complements. An easy consequence is again the description of the Cartan-Subalgebras in the case of