High-risk human papillomavirus (HR-HPV) and other sexually transmitted infections (STIs-O) are promoters to the development of cervical cancer (CC), especially when they co-exist. This study aims to determine the prevalence of the major STIs-O and the rate of co-infection in women previously diagnosed with HR-HPV infection. For this observational study, 254 women aged 25-65 years who were being followed up for HR-HPV infection (without a CC history) were recruited at a hospital's Gynaecology Department from February 2024 to November 2024. Their endocervical specimens were collected and processed for HR-HPV, , , , and detection by RT-PCR using commercially available reagents and equipment. The overall rate of infection was 38.6% for HPV and 4.3% for ITSs-O (3.8% in HPV-negative women and 5.1% in HPV-positive women). The presence of ITSs-O in women aged 25-34 was higher in those with a persistent positive result for HR-HPV (20.0% vs. 4.2%). Diverse multiple co-infections were found in HPV-positive women, whilst some single STIs-O were found in HPV-negative women. These results support the benefits of STI-O screening beyond an HR-HPV positive result, especially in those women under 35 years old.