The current study aimed to evaluate the efficacy of linked color imaging (LCI) in improving the visibility of superficial non-ampullary duodenal epithelial tumors (SNADETs). We prospectively evaluated 44 consecutive patients diagnosed with SNADETs. Three trainees and three experts assessed the visibility scores of white light imaging (WLI), LCI, and blue laser imaging-bright (BLI-b) for SNADETs, which ranged from 1 (not detectable without repeated cautious examination) to 4 (excellent visibility). In addition, the L* a* b* color values and color differences (ΔE*) were evaluated using the CIELAB color space system. For SNADETs, the visibility scores of LCI (3.53 ± 0.59) were significantly higher than those of WLI and BLI-b (2.66 ± 0.79 and 3.41 ± 0.64, respectively). The color differences (ΔE*) between SNADETs and the adjacent normal duodenal mucosa in LCI mode (19.09 ± 8.33) were significantly higher than those in WLI and BLI-b modes (8.67 ± 4.81 and 12.92 ± 7.95, respectively). In addition, the visibility score of SNADETs and the color differences in LCI mode were significantly higher than those in WLI and BLI-b modes regardless of the presence of milk white mucosa (MWM). LCI has potential benefits, and it is considered a promising clinical modality that can increase the visibility of SNADETs regardless of the presence of MWM.This study was registered at the University Hospital Medical Information Network (UMIN000028840).