The organisational culture of a health facility has been identified as a significant factor for successful implementation of clinical information systems. There have been no reported studies exploring the link between sub-cultures and the use of information systems. This study utilises cross sectional surveys to measure doctors' and nurses' perceptions of organisational culture and relate this to their use of a hospital-wide mandatory computerised pathology order entry (CPOE) system. 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. We identified subcultures based on professional divisions where doctors perceived an aggressive/defensive culture (mean percentile score = 43.8) whereas 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. The manifestation of subcultures within hospitals and the impact this has on attitudes towards clinical information systems should be recognized and addressed when planning for system implementation.