Arbitrary amplitude solitary kinetic Alfvén waves (KAWs) in a plasma with q–nonextensive electrons are investigated by the conventional Sagdeev pseudopotential method, through which the existence of solitary KAWs is analyzed theoretically and numerically. It is shown only solitons with density hump can exist, the amplitude of which depends sensitively on the parameter q and the plasma β. There is an upper limit for the amplitude of solitary wave which decreases with the increase of q and β. The results obtained in the framework of Maxwellian distribution are reproduced when q → 1.