The road passes through Lismore – Fermoy (M8) – Mallow (N20) – Rathmore – Killarney (N22) – Killorglin.

The N72 begins in County Waterford at the N25 near Dungarvan on the main Cork to Rosslare road.

Past Lismore the road is of poorer quality, travelling via Tallowbridge and Fermoy to Mallow in County Cork.

After the R579 junction, this section of the N72 has no hard shoulders until it joins the N22 in County Kerry, east of Killarney.

Further west, after bypassing Killarney, the N72 leaves the N22 again, becoming part of the Ring of Kerry route to Killorglin, where the road terminates at the N70.