Background: Social support positively affects the adaptation process of the woman to the maternal role during pregnancy and the postpartum period and increases her sensitivity to her baby. It is known that the support provided by fathers to their wives during this process positively affects their decision to breastfeed and continue. Purpose: The aim of this study is to contribute to the literature by the Paternal Support Scale of Breastfeeding, testing its validity, reliability and psychometric properties. Methods: The study, which included 203 fathers with babies 0–6 months of age who were actively breastfed between January and June 2022, was completed in a Medical Faculty Hospital at Konya in Turkey. The psychometric properties of the scale were evaluated with exploratory factor analysis and confirmatory factor analysis. In addition, number/percentage, t-test for dependent and independent groups and correlation analysis were used in the evaluation of the data. Results: Total item correlation coefficient of this scale was found to vary between 0.63 and 0.81. According to the confirmatory factor analysis results the goodness-of-fit index values of the scale indicated that the model has an acceptable fitness, and the 21-item one-dimensional scale has confirmed validity. Conclusion: Our findings showed that this scale is a good reliable measurement tool that can be used to evaluate levels of paternal support in breastfeeding. The scale can be adapted to different cultures, and cross-cultural comparisons can be planned in future studies. Practice implications. Spouse and family support increases breastfeeding success. Due to their active role in the decisions made within the family, fathers positively influence mothers' breastfeeding decisions and increase mothers' motivation to continue breastfeeding. This measurement tool, developed to measure partner support in breastfeeding, helps nurses, to determine fathers' support levels in breastfeeding. In this way, nurses can contribute to increasing the duration of breastfeeding by making effective interventions for the solution of partner support problems related to breastfeeding.