Based upon organizational theory, the purpose of this research was to identify and describe similarities and differences in the work environments of nine different types of nursing subunits (intensive care, medical, surgical, psychiatric, auxiliary, rehabilitation, rural, paediatric and obstetrical) in hospitals. Six measures of nursing subunit environment were developed: these included measures of nursing subunit autonomy, and the complexity and pervasiveness of other medical and hospital groups interacting with the nursing subunit. Data were collected by questionnaire from headnurses in 157 nursing subunits located in 24 hospitals in Alberta, Canada. The results indicated that the types of nursing subunits were similar in their degree of autonomy from both physicians and administration in the larger context in which they were located but were significantly different in terms of number and heterogeneity of groups outside nurses with which they interacted and the extent to which such groups pervaded the subunits. For example, intensive care units appeared as the type of nursing subunit with the greatest need for interaction with physicians, paramedics, hotel services and so on, whereas, psychiatric subunits appeared to be the least dependent on groups outside nursing in the hospital. These findings have implications for the management practices and educational programme for nursing.