In this paper, we study quasi-abelian codes over a finite chain ring. First of all, we provide a decomposition of a group ring \(\mathcal {R}G\) through character theory for a given commutative group G and a finite commutative chain ring \(\mathcal {R}\) . Further, we characterize a special 2-quasi-abelian code over a finite chain ring \(\mathcal {R}\) to be a linear complementary dual (LCD). Moreover, we give a method of construction of 2-quasi-abelian codes over a finite chain ring \(\mathcal {R}\) from 2-quasi-abelian codes over a finite field \(\mathbb {F}_q\) . Finally, we show that the class of LCD 2-quasi-abelian codes over a finite chain ring \(\mathcal {R}\) is asymptotically good.