Thirteen per cent of men aged 20 to 24 are infected with chlamydia, early data from a screening programme has shown.
Chlamydia is often a 'silent' infection
Figures presented at the Health Protection Agency's annual conference show more than 180,000 young people have been screened since 2003.
Screening, for under 25s across England, is available in a range of locations including youth clubs.
The HPA data also showed 12% of young women aged 16 to 19 were infected with chlamydia, which can damage fertility.
Overall, the programme has found one in 10 men and women had chlamydia.
Chlamydia is a "silent" infection. People commonly have no symptoms but can still pass the infection on to a sexual partner.
It can be easily treated once it has been detected, but if left untreated chlamydia can cause pelvic inflammatory disease, ectopic pregnancy and infertility in women and epididymitis (pain and swelling around the testicles) and Reiter's Syndrome (arthritis) in men.
Dr Mary Macintosh, who directs the programme at the HPA said: "Although the highest proportion of screens continue to be performed in community contraceptive services, an increasing number now take place in non-health settings, for example university, college, prison and military settings.
"Postal screening kits have also been introduced and are offered by an increasing number of areas."
She added: "Great strides have also been made in increasing the number of men screened.
"Between the first and third year the proportion of men screened has more than doubled from 7% to almost 20%."
"The importance of young people accessing this programme cannot be understated.
"Chlamydia is the most common sexually transmitted infection in England, with 96,204 diagnoses in genitourinary medicine clinics in 2005. "
She stressed all young people should use a condom with all new and casual partners.