Background: Endotracheal suctioning was authorized to be performed by individuals after attending a training course even though they do not possess a medical/nursing qualification in 2012 in Japan, though it is still considered as an evasive medical procedure. Objectives: This paper aims to discover experienced nurses’ proficiency of endotracheal suctioning in order to discuss future solution of nursing delegation. Methods: EMR-9○R (NAC Image technology Inc.) was used for eye tracking. EMR-dFactory○R version 2.7.0 was used for data analysis. ES was separated into six phases. Performance time, visual pathways, and movement speed of each participant were then analysed. Participants: Participants were recruited by snowball method and bulletin board. Inclusion criteria for nurses were experience of endotracheal suctioning in real work at any institution, and for students no experience of endotracheal suctioning in real settings. Results: Nurses' average time for ES was significantly shorter than students’; however, there was no significant correlation between years of 4 experience and the time (p= -0.006). Bimodality of eye movement velocity at 0-40 and 180-220 deg./s was also observed in the nurses’ group, in contrast to the unimodal distribution of the students’ velocity. Conclusion: Nurses achieved both time-efficiency and risk-avoidance by quickly gathering adequate visual information. Preparations before procedure to avoid task multiplicity are also important