Objective: To measure doctors' and nurses' perceptions of organisational culture and relate this to their attitudes to, and satisfaction with, a hospital-wide mandatory computersed provider order entry (CPOE) system in order to illuminate cultural compositions in CPOE use. Methods: A cross-sectional survey design was employed. Data were collected by administering an organisational culture survey (Organisational Culture Inventory, OCI) along with a user-satisfaction survey to a population of 103 doctors and nurses from two clinical units in an Australian metropolitan teaching hospital. Clinicians from the hospital had used the CPOE system since 1991 to order and view clinical laboratory and radiology tests electronically for all patients. The OCI provides a measure of culture in terms of three general styles which distinguish between: Constructive; passive/defensive, and aggressive/defensive cultures. The cluster which best describes the overall culture is the one that has the highest percentile score when the percentile scores of the four cultural norms included in the cluster are averaged. The user satisfaction survey asked questions relating to satisfaction with, and attitudes to, the system. Results: We found identifiable sub-cultures based on professional divisions where doctors perceived an aggressive-defensive culture (mean percentile score = 43.8) while nurses perceived a constructive culture (mean percentile score = 61.5). There were significant differences between doctors and nurses on three of the attitude variables with nurses expressing more positive views towards CPOE than doctors. Conclusion: The manifestation of sub-cultures within hospitals and the impact this has on attitudes towards clinical information systems should be recognized and addressed when planning for system implementation. Identification and management of the cultural characteristics of different groups of health professionals may facilitate the successful implementation and use of clinical information systems.