The chassis was designed by Rory Byrne, Giorgio Ascanelli, Aldo Costa, Marco Fainello, Willem Toet, and Nikolas Tombazis, with Ross Brawn playing a vital role in leading the production of the car as the team's technical director and Paolo Martinelli assisted by Giles Simon leading the engine design and operations.

The F399 was almost identical to the previous season's F300, with small detail changes like a new front wing, wheel tethers, waisted sidepods, and an improved exhaust system and the use of Bridgestone tyres with four grooves instead of three.

[4] Changes from the F300 were that the front wing was slightly modified, the sidepods were waisted, and the exhaust was improved in order so that Ferrari could push harder in their fight with McLaren.

[5] Early in the season the car showed huge performance with Irvine winning the opening round in Australia while Schumacher collected podiums along with wins at Imola and Monaco, thereby making Ferrari a serious threat to the McLaren duo of Mika Häkkinen and David Coulthard throughout much of the 1999 season.

[7] The team were briefly excluded from Malaysia after the stewards found out that their bargeboards were illegal, meaning that Häkkinen and McLaren were effectively handed their respective championships by default.