Simulation training for minimally invasive colorectal procedures is in developing stages. This study aims to assess the impact of simulation on procedural knowledge and simulated performance in laparoscopic low anterior resection (LLAR) and robotic right colectomy (RRC).LLAR and RRC simulation procedures were designed using human cadaveric models. Resident case experience and simulation selfassessments scores for operative ability and knowledge were collected before and after the simulation. Colorectal faculty assessed resident simulation performance using validated assessment scales (OSATS-GRS, GEARS). Paired t-tests, unpaired t-tests, Pearson's correlation, and descriptive statistics were applied in analyses.Barnes-Jewish Hospital/Washington University School of Medicine in St. Louis, Missouri.Senior general surgery residents at large academic surgery program.Fifteen PGY4/PGY5 general surgery residents participated in each simulation. Mean LLAR knowledge score increased overall from 10.0 ± 2.0 to 11.5 ± 1.6 of 15 points (p = 0.0018); when stratified, this increase remained significant for the PGY4 cohort only. Mean confidence in ability to complete LLAR increased overall from 2.0 ± 0.8 to 2.8 ± 0.9 on a 5-point rating scale (p = 0.0013); when stratified, this increase remained significant for the PGY4 cohort only. Mean total OSATS GRS score was 28 ± 6.3 of 35 and had strong positive correlation with previous laparoscopic colorectal experience (r = 0.64, p = 0.0092). Mean RRC knowledge score increased from 9.4 ± 2.2 to 11.1 ± 1.5 of 15 points (p = 0.0030); when stratified, this increase again remained significant for the PGY4 cohort only. Mean confidence in ability to complete RRC increased from 1.9 ± 0.9 to 3.2 ± 1.1 (p = 0.0002) and was significant for both cohorts.Surgical trainees require opportunities to practice advanced minimally invasive colorectal procedures. Our simulation approach promotes increased procedural knowledge and resident confidence and offers a safe complement to live operative experience for trainee development. In the future, simulations will target trainees on the earlier part of the learning curve and be paired with live operative assessments to characterize longitudinal skill progression.