Objective: To develop an instrument to study family-centred care (FCC) in traditional open bay Neonatal Intensive Care Units (NICUs). Methods: The development process involved constructing instrument's items, establishing content validity by an expert panel and testing the instrument for validity and reliability with a convenience sample of 25 parents and 29 nurses from 6 Jordanian NICUs. The tool covered FCC concepts of respect and dignity, information sharing, participation, and collaboration. Results: Both forms have satisfactory content, discriminant and construct validity. Cronbach's alpha was 0.91 for the parents' form and 0.93 for the nurses' form. While there was variation in parents' and nurses' perspectives on some aspects of FCC, the overall perspective of parents in the current study did not reflect a good application of FCC. Conclusion: This study led to the development of a validated instrument for face and content validity, construct (discriminant and convergent) validity and reliability.