MANY of the hundreds of thousands of backpackers who visit Australia each year are putting their health at risk by having unsafe sex.

About half of all young travellers have casual sex while they are in Australia, and the Family Planning Association (FPA) said studies had found at least one third of backpackers don't use condoms for casual sex.

"Unprotected casual sex places backpackers at particular risk because as travellers they often spend time in areas where HIV and other sexually transmitted disease infection patterns are different from those with which they are familiar," Sydney-based sexual health expert Dr Linda Dayan said.

"Several international studies show that a significant proportion of sexually transmitted infections (STIs) are acquired while abroad."

In conjunction with sexual health clinics, FPA NSW is launching Safe in the Sack, a sexual health awareness campaign aimed at backpackers.

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