•TTMV-HPV DNA testing to aid HPV-positive OPSCC diagnosis was prospectively evaluated.•Testing was feasible and perceived as clinically useful by treating physicians.•Among 3 subjects diagnosed with HPV-positive OPSCC, 2 had detectable TTMV-HPV DNA.•Undetectable TTMV-HPV DNA may not reliably indicate absence of disease.•Clinicians using this test should be aware of both its strengths and limitations. While survival outcomes are favorable for Human Papillomavirus (HPV)-positive oropharyngeal squamous cell carcinomas (OPSCCs), early diagnosis may minimize treatment-related morbidity and mortality. This study evaluated circulating tumor tissue-modified viral (TTMV)-HPV DNA plasma testing to facilitate early diagnosis of HPV-positive OPSCCs. In this prospective exploratory cohort study, patients presenting to an Otolaryngology-Head and Neck Surgery clinic with unexplained signs or symptoms considered high-risk for HPV-positive OPSCC were recruited between March 2021-October 2022. Circulating TTMV-HPV DNA testing was performed, and results were shared with subjects and treating clinicians. Clinicians were surveyed regarding the perceived clinical utility of the test. Thirty-nine subjects were included. Most subjects were women (N = 23, 59 %), white (N = 32, 82 %) and never-smokers (N = 20, 51 %) with median age 60 years. Circulating TTMV-HPV DNA was detected in 2/39 subjects, both subsequently diagnosed with HPV-positive OPSCC. Both were white men aged 70–80 years with a neck mass. One subject with undetectable TTMV-HPV DNA was also diagnosed with HPV-positive OPSCC through excisional neck mass biopsy. Other eventual diagnoses included 3 HPV-negative head and neck squamous cell carcinomas and 4 other malignancies. Testing was perceived as helpful in clinical decision-making for 26/38 (68 %) subjects, and useful for similar future patients for 32/37 (86 %) subjects. Circulating TTMV-HPV DNA testing is feasible and holds potential as a diagnostic aid for HPV-positive OPSCC alongside standard clinical workup. Clinicians should be cognizant of its limitations, as a negative test does not necessarily indicate the absence of disease. Further studies to evaluate its utility are warranted.