Objective: To analyze factors that lead nurses and doulas to have positive views of each other. Design: A multivariate analysis of a cross-sectional survey, the Maternity Support Survey. Setting: Online survey with labor and delivery nurses, doulas, and childbirth educators in the United States and Canada. Participants: A convenience sample of 704 labor and delivery nurses and 1,470 doulas. Methods: Multiple regression analysis was used to examine five sets of hypotheses about nurses' and doulas' attitudes toward each other. Scales of nurses' attitudes toward doulas and doulas' attitudes toward nurses included beliefs that nurses/doulas enhance communication, are collaborative team members, enhance a woman's birth experience, interfere with the ability to provide care, or interfere with relationships with the women for whom they care. Results: For nurses, exposure to doulas in their primary hospitals was associated with more positive views, whereas working more hours, feeling overworked, and a preference for clinical tasks over labor support were associated with more negative views of doulas. For doulas, working primarily in one hospital and certification were associated with more positive views of nurses. Nurses with more positive attitudes toward common obstetric practices had more negative attitudes toward doulas, whereas doulas with more positive attitudes toward common obstetric practices had more positive attitudes toward nurses. Conclusion: Our findings show factors that influence mutual understanding and appreciation of nurses and doulas for each other. These factors can be influenced by educational efforts to improve interprofessional collaboration between these maternity care support roles.