Objective The objective of this study was to determine the effectiveness and morbidities of two different tongue base surgical approaches in patients with obstructive sleep apnoea (OSA). Design and Setting We carried out a prospective analysis in order to understand in detail the relative impact on apnoeas of the two different tongue base procedures. Seventy cases in 85 patients with OSA were divided into two operating groups and randomized. Altogether, 37 transoral robotic surgeries (TORS) and 33 coblations were performed. The patency of retrolingual passage was investigated by Muller's manoeuvere, polysomnography. Apnoea-hypopnea index (AHI) was the primary outcome measure with the Epworth Sleepiness Score (ESS). The final follow-up visit was at 6 months. Results The AHI index improved from 29.7 +/- 9 to 10.7 +/- 3.9 (P < .005) following TORS and from 27.2 +/- 6.4 to 10.3 +/- 4 in the coblation group. Selecting a threshold of a 50% reduction in AHI and AHI less than 20 events/h, the overall success rate was 75.6% in TORS compared with 78.7% in coblation (P = .785). Similar results were seen in AHI reduction rates (36%, 37.8%, respectively). ESS showed a significant improvement 6 months following surgery in both groups. Conclusion Transoral robotic surgery technique showed higher complication rates than coblation. TORS and coblation of the tongue base represent a promising treatment option with a similar AHI improvement. However, coblation promises lower complication rates unlike TORS.