The 22-year-old was included the 24-man list released by for the 2019 Africa Cup of Nations (AFCON) doubleheader clash against Libya.
The invitation comes after Success last featured for the Super Eagles in an international friendly against Senegal in March, 2017 which ended in a draw at the Hive Stadium in London.
Since his last appearance for the Super Eagles the team has gone on to qualify for the and were knocked out in the group stage.
Watford congratulated Success on his latest achievement on their official Twitter account.
The club posted a message in reply to the tweet by the Nigeria Football Federation (NFF) which announced the official team list.
The message said, "Congratulations to #watfordfc forward @SuccessIsaac, who has been called up to the Nigeria squad!"
Success has been in good form for Watford this season especially in the and Reading.
The Super Eagles take on Libya on in Uyo on Saturday, October 13 before they travel abroad to take on Libya in the second leg scheduled for Tunisia.
Before he returns to the Super Eagles fold, Success is expected to be in action when Watford host AFC Bournemouth on Saturday, October 6 in their last game before the international break.