Unlike previous elections that produced a large unambiguous majority for the Ulster Unionist Party, this one gave more complex results. The Ulster Unionists were divided over a variety of reforms introduced by Prime Minister Terence O'Neill and this division spilled over into the election with official Ulster Unionist candidates standing either in support of or opposition to O'Neill and a number of independent pro O'Neill Unionists standing against opposing candidates. The results left O'Neill without a clear majority for his reforms and he resigned not long afterwards.
This was the first (and only) election since the 1929 general election to see changes to the constituencies. The Queen's University of Belfast seat was abolished and four new constituencies were created in the suburbs of Belfast to compensate for population growth there.
^23 Ulster Unionist MPs were pro-O'Neill, while 13 of them were anti-O'Neill. The results left O'Neill without a clear majority for his reforms and he resigned not long afterwards.