“Be hospitable and friendly — don’t hit anyone,” said the city’s mayor Alexander Yaroshuk.
“If you speak English, have a chat,” he added, giving his tips to residents on a talk show at local station Radio Komsomolskaya Pravda.
Kaliningrad is Russia’s westernmost World Cup host city in an exclave wedged between Poland and Lithuania.
It is building a new 35,000-seat stadium that will host four matches during the tournament.
The mayor asked residents to volunteer for a clean-up of city streets ahead of the matches.
But he encouraged locals to head out of town during the games.
“There will definitely be days off — we are now agreeing this with employers — so people who don’t have tickets go and take a break, because the city will be overcrowded,” the mayor said.
He warned the city will host some 150,000 supporters and will be virtually inaccessible to traffic except shuttle buses.
“Out of four matches at least one will have a good European team,” Yaroshuk said.
“Just imagine 100 to 150 thousand people will arrive, and they will wander round the whole city,” he warned.
“It’s better to plan to leave the city to have a holiday in the countryside.”
The advice echoes that given during Moscow’s 1980 Olympics, when the Soviet authorities advised parents to send children to summer camps.
They also forced some “undesirable” people such as those with criminal records to leave the capital.