Purpose: The study was undertaken to evaluate the reliability and validity of hypoglycemia clinical judgment rubric which developed for investigation nursing student’s clinical judgement competency on hypoglycemia simulation practice. Methods: The study was a methodological study with 59 nursing students from Y University participating. Fifty video files were used to analyze nursing student’s clinical judgment competency. Rubric was consisted with 11 questions having 4 phases (beginning, developing, accomplished, and exemplary) and composed with 4 sub-categories (noticing, interpreting, responding and evaluation/reflecting). Results: The value of inter-rater reliability was r=.92 (p<.001) and Kendall tau b=.79 (p<.001). The value of intra-rater reliability was r=.92 (p<.001) and r=.99 (p<.001). Cronbach's α was .93 as internal consistency reliability. Construct validity by factor analysis, 3 factors were extracted and it explained 80.9% of the variance in clinical judgment competency. The value of competency of hypoglycemia clinical judgment was 2.47 (±.42). Conclusion: The hypoglycemia clinical judgment rubric can be used for assessing clinical judgment competency on simulation practice. Also, it can be applied for evaluation a clinical judgment as a nursing program outcome of nursing students.