Party officials opted not to automatically reselect Mohammad Asghar, prompting an open contest.
On Thursday night it was announced Mr Asghar had topped the poll.
A second AM forced to follow the same procedure, William Graham, finished outside the top  four - meaning he is effectively de-selected.
Second on the list will be Laura Anne Jones, previously an AM between 2003-07.
In a statement, Mr Graham said: "Whilst I am personally disappointed that I will not be part of an expanding Welsh Conservative team after the elections in May, I remain as invested as any of my colleagues in the goal of bringing an end to this tired Labour government."
The Conservatives currently hold two of the available four seats in South Wales East.
The 60 AMs include 20 elected via regional lists, aimed to give a fairer reflection of support for each party.
A Conservative AM forced to face a ballot of party members has come top of the South Wales East regional list for the 2016 assembly election.