Telehealth technologies offer efficient ways to deliver health-related social needs (HRSN) screening in cancer care, but these methods may not reach all populations. The authors examined patient characteristics associated with using an online patient portal (OPP) to complete HRSN screening as part of gynecologic cancer care. From June 2021 to June 2023, patients in a gynecologic oncology clinic completed validated HRSN screening questions either (1) using the OPP (independently before the visit) or (2) in person (verbally administered by clinic staff). The authors examined the prevalence of HRSN according to activated OPP status and, in a restricted subgroup, used stepwise multivariate Poisson regression to identify associations between patient and visit characteristics and using the OPP. Of 1616 patients, 87.4% (n=1413) had an activated OPP. Patients with inactive OPPs (vs. activated OPPs) more frequently reported two or more needs (10% vs 5%; p<.01). Of 986 patients in the restricted cohort, 52% used the OPP to complete screening. The final multivariable model indicated that patients were less likely to use the OPP if they were Black (vs. White; adjusted relative risk [aRR], 0.70; 95% confidence interval [CI], 0.59-0.83); not employed (vs. employed; aRR, 0.81; 95% CI, 0.68-0.97), or had low measures of OPP engagement (aRR, 0.80; 95% CI, 0.68-0.92). New versus established patients were 21% more likely to use the OPP (aRR, 1.21; 95% CI, 1.06-1.38). Differential use of the OPP suggested that over-reliance on digital technologies could limit the ability to reach those populations that have social factors already associated with cancer outcome disparities. Cancer centers should consider using multiple delivery methods for HRSN screening to maximize reach to all populations.