Background. Trichomonas vaginalis (TV) is themost common nonviral sexually transmitted infection (STI) in the world. However, TV is not a reportable STI and, with the exception of HIV-positive women, there are no guidelines for screening in women or men. The objective of this study was to determine the added value of nucleic acid amplification tests (NAATs) for detection of TV in men and women at high risk for infection as well as correlates of infection. Methods. This was a review of clinical and laboratory data of men and women presenting to the Jefferson County Department of Health Sexually Transmitted Diseases (STD) Clinic and receiving a TV NAAT. Results. During 2012-2013, 6335 patients (3821 women and 2514 men) received a TV NAAT on endocervical, urethral, or urine specimens. Overall TV prevalence was 20.2%; 27.0% in women and 9.8% in men. Correlates of TV among men included age >40 years, African American race, and ≥5 polymorphonuclear cells per high-power field on urethral Gram stain. Age >40 years, African American race, leukorrhea on wet mount, elevated vaginal pH, positive whiff test, and concurrent gonococcal infection were positively associated with TV among women. TV NAAT detected approximately one-third more infections among women than wet mount alone. Conclusions. TV prevalence among men and women was high in this study, suggesting that both groups should be routinely screened, including those aged >40 years. Improved detection of TV by routine implementation of NAATs should result in better control of this common, treatable STI. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved.