Wollongong watering holes will stock more in their bars this month as part of a campaign to promote safe Valentine's Day loving.

Pub-goers at four pubs will receive free condoms with their pints in the lead-up to the day, very deliberately included in the sexual health campaign, The Big Gamble.

The campaign targets members of the heterosexual population who have recently changed partners and comes after a dramatic spike in chlamydia notifications in the region.

"When people start a new relationship they might not know the sexual background of the person they're having a relationship with and lots of sexually transmitted infections (STIs) have no symptoms," Healthy Cities Illawarra sexual health promotion officer Naomi Cox said.

"We thought Valentine's Day was an appropriate time to get that message out there and get people thinking about their sexual health.

"Along with the presents and love that comes with Valentine's Day, we also encourage people to use condoms and be aware of sexually transmitted infections."

Chlamydia notifications to South Eastern Sydney Illawarra Area Health Service tripled between 2000 and 2006, with a particularly large spike recorded between 2004 and 2005.

Condom packs, together with coasters and posters bearing the safe sex message, will be distributed to the University of Wollongong Unibar, the Beach Bar, North Gong Hotel and the Harp Hotel.

Healthy Cities recommends people beginning a new relationship have a sexual health check-up, particularly if they don't plan to use condoms. Those who recently ended a relationship, had unsafe sex or whose partner had an STI should also have a check-up.