One in four children younger than 25 said that school sex education lessons were inadequate.
Instead, just over 50 percent get their information from the Internet, favouring discussion forums and social networking sites, the survey by condom maker found.
Another 36 percent turn to friends and peers for advice.
Uninformed and unprepared, a majority of teens (57 percent) admitted to not enjoying their first sexual encounter.
Shockingly, 15 percent do not use a condom, during sex.
According to Sexual Health Australia director Desiree Spierings, the sharp rise in chlamydia rates for teens aged 16 to 19 shows the safe sex message is missing some completely.
“Using social media is a new trend. You hear they ask for tips and advice on social networks and also they read blogs so they might not necessarily be professional sites they are getting their information from,” the Daily Telegraph quoted her as saying.
Sex education begins in NSW in early primary school under the personal development, health and physical education syllabus (PDHPE).
But one provider of sex classes in NSW primary and high schools, said more education was needed.
“They resort to wanting to find out questions via the Internet,” Interrelate director of services Dr Jonathan Toussaint said.
The government has classified young people as a priority target under the second national sexually transmissible infections strategy.
The report has found that 50 percent of teens are sexually active by the time they are 16.
“The average age of first exposure to pornography is 11 and dropping,” a youth welfare organisation founder said.
Her sex education program ‘Get A Grip teenz’ has already begun in Queensland and hopes to launch in NSW schools.
“Kids see sex at a younger age but can’t process what it means to them,” she said.
Year 8 students Emma McGuigan and Shanelle Peeti, both 13, learnt about safe sex in the first term of Year 7, and now they mostly talk about it with their friends.
They don’t have boyfriends and spend most of their free time surfing.
“We don’t ever talk about sex at home, we get most of the information from PE classes at school,” Emma, from Chifley, had said.
Her mother Lisa said that she tried to have the birds and the bees chat last year but dropped it - mainly out of awkwardness.
“Emma doesn’t want to talk to me about it so I presume they’ve talked about sex at school. I don’t want to expose her too early. I want to find the right time,” Lisa added.