Objectives: Endotracheal intubation is an important, time-critical, life-saving emergency medicine procedure. Laryngoscope characteristics might influence time to successful intubation. The objective of the present study was to determine whether laryngoscope light of variable intensity would influence the length of time required to achieve successful endotracheal intubation.Methods: An in vivo single-blind prospective randomized cross-over trial was conducted using a variable light source laryngoscope and three clinically plausible intensities of light – high (600 lux), medium (200 lux) and low (50 lux). Thirty-six volunteer senior emergency medical staff repeatedly intubated two manikins three times each, based on one of six randomly assigned permutations of light intensity. The primary end-point was time to successful intubation.Results: There was no statistically significant difference in time to intubation versus light intensity for either manikin.Conclusion: The intensity of laryngoscope light across a clinically plausible range does not affect time to intubation.