The three Swiss – Josef Wyer, Werner Zimmermann and Beat Studer – left Küssnacht am Rigi in the canton of Schwyz on June 9th.
They completed the 12-stage 1,800 km journey on Thursday when they drove into Kaliningrad on their 54-year-old red and white tractor, known as Gritli.
In a Facebook post the three announced they had arrived without incident from Elblag in Poland.
However, they did have one anxious moment while crossing Poland when they were stopped by police after taking a wrong turn, 20 Minutes reported.
The three Switzerland supporters are raising money on their trip for a charitable foundation, Joy Prevails, set up by former Swiss sport minister Adolf Ogi.
The Switzerland-Serbia clash starts at 8pm on Friday.
Friday's game could decide the fate of Group E, with both sides vying for a single last-16 spot alongside Brazil.
Swiss coach Vladimir Petkovic has vowed his side will maintain the robust approach that earned them a draw against Brazil in their first World Cup match, AFP reported.