Studies applying transcranial direct-current stimulation (tDCS) to motor regions to enhance surgical skills have observed modest benefits in performance. Early surgical skills acquisition is known to be dependent on the prefrontal cortex (PFC) which could be a suitable target for performance enhancement in fields with high cognitive demand. To assess whether prefrontal tDCS could improve early phases of surgical skill development. In a randomized sham-controlled double-blind parallel design, 40 surgical novices performed an open knot-tying task repeated in three blocks; pre-, online- and post-tDCS. During online stimulation, participants were randomized to either active tDCS (2 mA for 15 min) to the prefrontal cortex (anode over F3, cathode over F4) or sham tDCS. Performance score (PS) was computed using a validated algorithm and introspective workload domains were assessed using a SURG-TLX questionnaire. There was no difference in demographics or PS between groups prior to receiving tDCS. PS significantly improved from pre-to online- (p < 0.001) and from pre-to post-tDCS (p < 0.001) in the active group only. Following active tDCS, PS was closer to the defined proficiency benchmark and significantly greater compared to sham (p = 0.002). Only the active group reported significantly improved temporal demand scores from pre-to online- (p = 0.004) to post-tDCS (p = 0.002). This study demonstrates significantly improved early phase surgical-skill acquisition following prefrontal tDCS. Further work is required to determine the underlying neurophysiological mechanisms and whether the benefits observed are retained long-term.