The relationship between a mother and her newborn can be determined through two concepts: “bond” and “attachment.” Currently, there are no instruments that assess these phenomena jointly. Objective. This study aims to develop a valid and reliable instrument to determine the quality of the postnatal bond and attachment in the mother‐child relationship. Methods. In Spain, a multidisciplinary panel of experts was involved in creating the “Maternal‐Child Bond and Attachment (VAMF, for its initials in Spanish)” tool. The tool was piloted on a group of women and applied to the target population of women with children aged between 6 weeks and 18 months to determine the psychometric characteristics: internal consistency Cronbach’s α was used. An exploratory factor analysis was conducted, a study of convergent validity with the scale and predictive validity with the Maternal Postnatal Attachment Scale (MPAS) using Pearson’s correlation coefficient, and a study of reliability was carried out using the intraclass correlation coefficient. Results. 1155 women participated, with a mean age of 34.5 years. The VAMF showed good internal consistency for the scale with 29 items (α = 0.836). In the exploratory factor analysis (EFA), an explained variance of 49.71% was observed with 6 components. Convergent validity showed an adequate correlation, with a Pearson correlation coefficient with the MPAS scale of 0.679. The VAMF questionnaire presented an excellent predictive capacity in the bond subscale, with an area under the ROC curve of 0.90 (95% CI: 0.87–0.93), and a poor predictive capacity in the attachment subscale, with an area under the ROC curve of 0.69 (95% CI: 0.63–0.76) to predict MPAS scale scores. In the test‐retest, the VAMF presented a very good adequate degree of absolute agreement (ICC: 0.86; 95% CI: 0.72–0.93). Conclusions. The VAMF is a new valid and reliable instrument for determining the quality of the mother‐child bond and attachment.
