Background: This study translated and culturally adapted the Comfort Behavior Scale (Comfort-B) into Vietnamese using a standard protocol guided by the World Health Organization. Methods: The Comfort-B was translated into Vietnamese and then English back-translated by independent translators. These versions were reviewed and assessed by a Vietnamese expert’s panel and an English expert’s panel. Thirty-four nurses of the Nhi Dong 1 Hospital were invited to use the Vietnamese Comfort-B to assess pain while watching five videos recorded before, during and after wound dressing replacement. The eight characteristics of the Vietnamese Comfort-B were assessed by 34 nurses. Fifteen nurses agreed to do the second assessment two weeks from the first assessment. The content validity index was used to assess the relevance and clarity of all items and the whole scale. Agreements between raters were explored using Kappa statistics. Intraclass correlation coefficients (ICC) were used to assess intra-rater and inter-rater reliability. Multi-level linear regression was used to assess changes in the Vietnamese Comfort-B before, during and after wound dressing replacement between two assessments. Results: The Vietnamese Comfort-B was accredited by the Vietnamese expert’s panel. The English-back translated version was approved by the English expert’s panel. The nurses agreed that the Vietnamese Comfort-B can be used in clinical practice and research. Kappas of all items were ≥0.96 indicating excellent agreement between raters. Alpha coefficients of two assessments were ≥0.97 indicating excellent internal consistency. All ICCs ≥ 0.79 indicated good intra-rater and inter-rater reliability. Conclusions: The study suggested that the Vietnamese Comfort-B can be used for future studies assessing children’s pain in the local hospital context.