Background The Baska mask and i-gel are two new types of second-generation supraglottic airway devices. The aim of this study was to compare these two devices in terms of quality of insertion, quality of ventilation and post-insertion complications. Methods A total of 80 adult patients who were scheduled for elective surgery under general anaesthesia were randomised to two groups: Group BM: Baska mask ( n = 40) and Group IG: i-gel ( n = 40). The assessment focused on ease of insertion, number of attempts, insertion time, number of corrective manoeuvres, oropharyngeal leak pressure, tidal volume, peak airway pressure (PAP) and post-insertion complications. Results Group IG showed a significantly shorter median insertion time (13.3 [interquartile range, IQR 7.8] vs. 17.0 [IQR 9.6] s; P < 0.001), a higher percentage in the ‘very easy’ ease of insertion category (62.5% vs. 10.0%; P < 0.001), a higher percentage in the no corrective manoeuvre category (92.5% vs. 72.5%; P = 0.003) and a higher percentage in the no post-operative throat pain category (67.5% vs. 32.5%; P = 0.011) than Group BM. However, Group BM showed a significantly higher generated PAP than Group IG (12.7 [1.8] and 11.5 [2.2] cm H 2 O, respectively; P = 0.010). There were no significant differences in other parameters. Conclusions The i-gel was better than the Baska mask in terms of ease of insertion, speed of insertion, fewer corrective manoeuvres and less post-operative throat pain. However, the Baska mask had a better cuff seal, as shown by a higher generated PAP.