A study explored the nature of collaborative learning as a method to prepare future nurses for collaboration in health care. Qualitative research data collection and analysis methods were used. A constant comparative method occurred during and after the data were gathered. Semi-structured interviews, focus groups, and document review were the primary sources of data. Eleven nurses who provide direct patient care and 14 nurse educators who use collaborative learning in nursing education participated. Data analysis suggested collaboration in health care is essential and preparation for collaboration is vital. Collaboration was identified as a core value of nursing and embedded throughout nursing practice. Study participants indicated that collaborative learning experiences provided the structure or framework to facilitate professional socialization. The theory developed from the data analysis was Collaborative Learning as Professional Socialization. The following principles of this theory could be used as guidelines for developing nursing education curriculum as professional socialization: learning to collaborate is a developmental process, and it requires knowledge, skills, developing positive attitudes, and values. (Contains 124 references.) (YLB)