ABSTRACTTrichomoniasis (TV), bacterial vaginosis (BV), and vulvovaginal candidiasis (VVC) are the most common causes of vaginitis. This study investigated the prevalence of these diagnoses, their associated factors, and the appropriateness of the empirical treatment. From March 25, 2019, to June 17, 2022, 429 women with symptoms or signs of vaginitis were enrolled in a hospital in northern Taiwan with 438 episodes of vaginitis. Vaginal swabs were collected for Gram’s staining,in vitrocultures forTrichomonas vaginalis, bacteria, and yeasts, and multiplex PCR assay for TV, BV, and VVC. Their empirical treatments were recorded. Factors associated with different etiologies of vaginitis were sought in multivariable logistic regression models. The prevalence of TV, BV, and VVC were 2.1%, 22.8%, and 21.7%, respectively, while coinfections of BV and VVC, TV and BV, TV and VVC, and triple infection occurred in 5.0%, 0.2%, 0.2%, and 0.7%, respectively. Multivariable analyses revealed that having multiple sexual partners was associated with TV and BV (adjusted odds ratio [aOR] 9.756 and 3.246, respectively), while menopausal women were less likely to have VVC (aOR 0.184). Moreover, dysuria was associated with TV (aOR 4.981), vaginal itch and pelvic pain with VVC (aOR 3.223 and 0.425, respectively), and discharge pH > 4.5 with BV (aOR 1.767). Other clinical symptoms and pelvic examination features had limited value for differential diagnosis. Among the 78 empirical antifungal and metronidazole prescriptions, 55.2% were ineffective or unnecessary. Our study highlights the importance to integrate appropriate diagnostic tools into the clinical care of women with vaginitis.IMPORTANCEVaginal complaints are widespread among women and are associated with emotional, physical, and economic burdens with challenges in their diagnosis and management. In this survey, we identified that 40% of vaginitis in Taiwan was caused by either trichomoniasis, bacterial vaginosis, vulvovaginal candidiasis, or a combination of these infections. Our data suggested that typical physical findings appeared infrequently among women with these infections and their empirical treatments were frequently inappropriate. Our findings highlighted the importance of integrating proper diagnostic tools into clinical practice to improve the diagnosis and management of vaginitis, as recommended by national and international guidelines.