Carpal tunnel decompression is mostly performed as a day case procedure using local anaesthesia. The local anaesthetic is commonly administered by subcutaneous infiltration alone (the Gale technique) or by infiltration of the local anaesthetic into the carpal tunnel in addition to the subcutaneous infiltration (the Altissimi and Mancini technique). The intention of this study was to compare the efficacy of anaesthesia using these two techniques. Twenty patients with bilateral carpal tunnel syndrome were recruited. One side underwent surgery at a time. Patients were randomised to receive anaesthesia by one technique on the first side and the other on the second. Pain was evaluated using the numerical rating pain scale (0-10). Six patients experienced intraoperative pain with the Gale technique, while none had pain with the Altissimi and Mancini technique (P = 0.02). The postoperative pain was not significantly different between the two groups, although the patients anaesthetised by the Altissimi and Mancini technique required significantly lower numbers of analgesic tablets.