Al-Abdi, a former pilot in the Yemeni air force, was found guilty and in 2009 was sentenced to death by firing quad.
Yemen’s Supreme Court has now turned down an appeal by the al-Abdi family for him to only have to pay compensation.
Security officials said al-Abdi has showed no regret over the killing and saw it as a warning to other Yemeni Jews.
They described him as mentally unstable and alleged that he also killed his own wife two years before attacking Mr Nahari.
Before 1948 Yemen was home to around 60,000 Jews but that number has now dwindled to just 200.