For an integer $d\geq 3$ let $\alpha(d)$ be the supremum
over all $\alpha$ with the property that for every $\epsilon>0$ there exists some
$g(\epsilon)$ such that every $d$-regular graph of order $n$ and girth at least $g(\epsilon)$
has an independent set of cardinality at least $(\alpha-\epsilon)n$.
Extending an approach proposed by Lauer and Wormald
(Large independent sets in regular graphs of large girth,
{\it J. Comb. Theory, Ser. B} {\bf 97} (2007), 999-1009)
and improving results due to
Shearer (A note on the independence number of triangle-free graphs, II,
{\it J. Comb. Theory, Ser. B} {\bf 53} (1991), 300-307)
and Lauer and Wormald, we present the best known lower
bounds for $\alpha(d)$ for all $d\geq 3$.