Background The prognostic value of positive surgical margins after transoral laser microsurgery (TOLM) is still under debate. In case of positive superficial margins, some experts recommend a second-look surgery (SL) and some recommend wait and watch approach with close observation. Narrow band imaging (NBI) is an advanced imaging system used to enhance visualization of mucosal vascular pattern. In laryngology, NBI is used to improve the detection of premalignant, dysplastic and malignant lesions. Aim To assess the usefulness of NBI imaging in guiding clinical decision making regarding follow-up plan and SL after TOLM. Materials and methods A prospective cohort of 127 patients was divided into three groups based on the histology results and NBI vascular pattern of the mucosa. Group A (24/127, 18.90%) consisted of patients with suspicious vascular pattern in NBI or/and with positive deep margin. Group B (52/127, 40.94%) consisted of patients with positive or uncertain superficial margins and non-suspicious vascular pattern in NBI. Group C (51/127, 40.15%) had non-suspicious vascular NBI pattern and all negative margins. Results After the first TOLM procedure, 9/24 (37.5%) patients had positive deep margins, 1/24 (4.2%) had uncertain deep margin and 1/24 patient (4.2%) had both positive deep margin