Qazaishvili has spent the past six years with Vitesse of the Dutch Eredivisie, recording 25 goals and 10 assists over 104 league appearances. The 24-year-old spent the 2016-17 campaign with Polish side Legia Warsaw, appearing in 12 league games, two UEFA Champions League contests and two Europa League matches.
On the international level, Qazaishvili has five goals in 23 caps for Georgia.
"We were looking for a player, a younger, offensive player, that really excites the fans and has the possibility to stay with us for a long period of time. That's what we found with Vako," Earthquakes general manager Jesse Fioranelli said in a news release. "We wanted a player that knows how to take on a defender one-on-one, that sees the goal and that also wants to bring a spark to our game."
Qazaishvili will look to bolster an Earthquakes side that sits seventh in the Western Conference at 5-6-5. Only two teams in MLS — D.C. United and the Colorado Rapids — have scored fewer goals than San Jose's 16 this season.