  A generalised Struve function has recently been introduced by Ali, Mondal and
Nisar [J. Korean Math. Soc. {\bf 54} (2017) 575--598] as \[(\frac{1}{2}
z)^{\nu+1}\sum_{n=0}^\infty\frac{(\frac{1}{2} z)^{2n}}{\Gamma(n+\frac{3}{2})
\Gamma(an+\nu+\frac{3}{2})},\] where $a$ is a positive integer. In this paper,
we obtain the asymptotic expansions of this function for large complex $z$ when
$a$ is a real parameter satisfying $a>-1$. Some numerical examples are
presented to confirm the accuracy of the expansions.
