The direct ascent of Mòruisg starts on the A890 road in Glen Carron at a parking spot one kilometre west of Loch Sgamhain at grid reference . After crossing the River Carron by the footbridge it a steep climb of almost 800 metres to reach the summit through heather and scree. Almost all ascents of Mòruisg are combined with the neighbouring Munro of Sgurr nan Ceannaichean. Approaches are possible from the south using well graded stalkers' paths; one of these leaves the valley of the Allt a' Chonais and climbs Sgurr nan Ceannaichean first before continuing to Mòruisg. Another path starts at Glenuaig Lodge and climbs the precipitous southern slopes direct to the mountains summit.