Nurses play an important role in pharmaceutical care worldwide in detecting clinical changes, communicating and discussing pharmacotherapy with patients, their families, and other healthcare professionals, proposing and implementing drug-related interventions, and ensuring the monitoring of patients and their medication regimens, among others. However, there is no global consensus across countries regarding the prescribing of medication by nurses. In Spain, for example, this topic is currently in transition since the approval of the Royal Decree 1302/2018 of October 22nd, which regulates the indication, use, and authorization for dispensing human-use medication by nurses. Our study aims to identify the enablers and barriers to advancing the nurse prescribing of medication in Spain through the views of experts in the field and according to the latest Royal Decree approved and the steps taken by the different Spanish autonomous communities. A modified qualitative Delphi study with three iterations was performed online through the perspectives of experts from the field of healthcare education, research, practice, management, and policy. Data extracted from the literature were used to formulate the open-ended questions utilized in the three rounds. The experts involved (n = 15) belonged to different Spanish regions where the Royal Decree is being implemented with different speeds, and had distinct backgrounds and experiences. Our results highlight the importance of prospectively developing additional protocols based on chronic diseases as well as scaling up towards independent nursing prescription, the inclusion of a joint multidisciplinary pharmaceutical care model, the controversial role played by national nursing councils and boards, the variability in the speed of implementation among the autonomous communities, and the lack of nursing training in the field of medication prescription.