Purpose Vascular invasion is considered a poor prognostic feature in papillary thyroid cancer (PTC), and a relative indication for radioactive iodine treatment (RAI). Intratumoral lymphatic and vascular invasion are difficult to distinguish pathologically, and are often grouped together as “lymphovascular invasion” (LVI). However, the significance of LVI as an independent risk factor in otherwise low-risk PTC is unclear. We sought to clarify the prognostic impact of LVI in T1 PTC. Methodology A retrospective cohort study of 1111 patients treated surgically for T1 PTC between 2016 and 2023 at a tertiary referral centre was performed, using prospectively collected data. Results 204 (18.4%) patients with T1 PTC had LVI and 19 (1.7%) patients developed disease recurrence. RAI therapy was used in 315 (28.4%) patients. Pathological factors determining the use of RAI included LVI, tumour size, aggressive histologic variant, margin involvement, multifocality and lymph node involvement. In 11 (3.5%) patients LVI was the single determinate of the use of RAI. LVI was associated with structural recurrence on univariate analysis (OR 2.65, 95% CI 1.03-6.82, p=0.043). On multivariable analysis, independent predictors of recurrence were lymph node involvement (OR 14.4, 95% CI 3.09-67.06, p<0.001) and involvement of >5 lymph nodes (OR 2.95, 95% CI 1.10-7.91, p=0.032). Conclusion The presence of LVI is not independently prognostic for disease recurrence in T1 PTC and, in the absence of other high-risk features, may not be an indication for RAI.