BACKGROUND:: Fatigue has been shown to have a negative impact on surgical performance. However, there is a lack of research investigating its effect on laparoscopy, particularly in Australia. This study investigated whether fatigue associated with a surgeonʼs usual workday led to a measurable drop off in laparoscopic surgical skills as assessed on a laparoscopic simulator. METHODS:: A comparative study involving two cohorts was undertaken: a study group whose data were collected prospectively was compared to a historical control group. Participants were required to reach a predetermined level of proficiency in each laparoscopic task on either a FLS or LapSim simulator. The participants in the study cohort were re-tested approximately 1 month after completing 10 h of work. The participants in the historical non-fatigued group were re-tested approximately 1 month after reaching proficiency. Comparisons between cohorts were made using a ‘decrease in score per day elapsed’ value to account for the natural attrition in skills over time and the variability in testing times within and between the two cohorts. RESULTS:: The decrease in overall score per day elapsed for fatigued participants was significantly greater than for historical non-fatigued participants, irrespective of the simulator type. Fatigue had a greater impact on certain laparoscopic skills, including peg transfer and knot tying. Participants who self-reported higher level of fatigue demonstrated significantly better skills than those who self-reported lower levels. CONCLUSION:: Overall laparoscopic skill proficiency was reduced in the fatigued participants compared to the historical non-fatigued participants, with certain laparoscopic skills more affected than others.