There are approximately 22 kilometres of trout fishing on the Nenagh River measured upstream from Annaghbeg Bridge and a further 15 kilometres on the Ollatrim upstream from where it joins the Nenagh River. It is primarily a brown trout river and gets a small run of spring salmon and grilse. It holds excellent stocks of ½ lb brown trout with some to five pounds and even better.
Access to the river banks is fair. The banks are high, difficult and overgrown, but worth the effort. Wading is essential in many areas. It has all the usual fly hatches associated with a rich lowland river, including mayfly.