Background: Nurses must be comfortable facilitating palliative and end-of-life communication with patients and their families. Aim: A validated instrument measuring the comfort of nurses with conducting end-of-life communication is essential for meeting the goals and wishes of patient care. This study aimed to develop and conduct a psychometric evaluation of the Comfort with Communication in Palliative and End-of-Life Care (C-COPE) instrument. Methods: Face, content, and construct validity, including test-retest reliability, were conducted. Results: Four experts subjectively confirmed face content validity and the quantitative item content validity index (I-CVI) ranged from 0.67 to 1 and scale content validity index (S-CVI/Ave) was 0.98. Principal axis factoring with Promax rotation yielded a five-factor solution accounting for 66.2% of the variance. The items loading on the five factors ranged from 0.46–0.96 (factor 1), 0.67–0.93 (factor 2), 0.49–0.86 (factor 3), 0.68–0.79 (factor 4), and 0.24–0.96 (factor 5). Internal consistency reliability (coefficient a) was 0.90 for the total C-COPE, and above 0.75 for each factor. The five factors are ‘cultural/spiritual considerations,’ ‘team considerations,’ ‘addressing decision-making,’ ‘addressing symptomatology,’ and ‘deliberate awareness.’ Test-retest reliability yielded an intraclass correlation coefficient (ICC) of 0.87 (CI 95%, 0.82–0.91). Conclusions: The C-COPE is a reliable and valid instrument measuring nurse comfort with palliative and end of-life care communication, yet requires testing in more diverse samples.