Sardar Ahmad, a 40-year-old journalist in AFP's Kabul bureau and a former stringer for Radio France Internationale, was killed along with his wife and two of their three children.
Four teenage Taliban gunman with palm-sized guns concealed in their socks circumvented several layers of security at the Serena hotel, an upmarket hotel popular among foreign visitors in the capital.
"This is an immensely painful and enormous loss for Agence France-Presse," said AFP chairman Emmanue Hoog, adding that Ahmad delivered daily exceptional coverage in very difficult conditions.
His last feature filed for AFP on Tuesday was about a lion rescued by animal welfare officials from living on a rooftop in Kabul -- a follow-up to a story he broke last year.
An AFP photographer identified the four bodies at a city hospital and said the family's youngest son was unergoing emergency treatment after being badly injured in the attack.
Ahmad joined AFP in 2003 and became the agency's senior reporter covering a range of beats including war and politics in his native Afghanistan.
The attack came just weeks ahead of Afghanistan's April 5 elections to pick the successor to President Hamid Karzai.
The Taliban, which claimed responsibility for the Thursday night attack, has repeatedly vowed a campaign of violence in a bid to disrupt the vote.