Chlamydia trachomatis is a widespread, sexually transmitted infection causing pelvic inflammatory disease, infertility, ectopic pregnancy and chronic pelvic pain among women. Asymptomatic infections among men contribute significantly to maintaining the spread of the infection. In a 1-y intervention study in general practices we aimed to evaluate an opportunistic screening programme targeting 16-25-y-old men. When the young men saw their general practitioner (GP) for the first time during the intervention y, they were offered a test for C. trachomatis based on a first catch urine sample. Main outcome measures were percentage of tested men and prevalence of infection in the intervention practices compared with the test activity in the rest of the county during the intervention y and the y before. GPs in the intervention practices saw 617 (75.6%) of the 814 registered young men during the intervention period. Screening was offered to 300 (48.6%) and 219 (26.9% of the target population) accepted the invitation. The prevalence of infection among screened men was 5.0%. We conclude that opportunistic screening for urogenital C. trachomatis infection in general practice is feasible.