Purpose Most of the existing studies on postcoital bleeding (PCB) in Western countries. To date, no study has focused on the various PCB-related comorbidities in Taiwan women. This work aims to analyze and compare the presence or absence of PCB among Taiwanese women with gynecological comorbidity. Methods This study is a population-based retrospective cohort investigation. Outpatients with PCB after the index date were considered. A total of 2377 female patients with PCB (ICD-9 626.7) were identified using a nationwide outpatient sample from 2001 to 2010. For comparison, 7131 cases were randomly matched with the study group in terms of gender and age. Resutls The PCB incidence rate was 39-59 cases/100,000 Taiwanese women, with mean age (+/- SD) of 36.74 +/- 10.79 years, median age of 36 years, and mode age of 29 years. Women with PCB exhibited 1.47-fold risk of cervical dysplasia and 1.59-fold risk for malignant neoplasm of cervix. Young women with PCB showed high risk of cervical cancer. The most common benign diseases among PCB- related comorbidities were cervical erosion and ectropion (20.66%), followed by vaginitis and vulvovaginitis (19.18%). Comparison between PCB and non-PCB groups indicated several significant high-risk comorbidities including cervical polyps, cervical erosion, leukoplakia of cervix, intrauterine contraceptive device, cervicitis, vaginitis, menopause, dyspareunia, and vulvodynia. Conclusions This study provides evidence that PCB-related comorbidities manifested benign diseases (51.58%), lower genital tract infection (46.11%), and cervical cancer (2.31%). Thus, healthcare providers must ensure that appropriate routine screening tests and counseling are given to women with PCB.