BackgroundThe growing demand for aged care services coupled with a global shortage of skilled nursing staff has hindered long-term care facilities’ ability to provide necessary services to their residents. Healthcare information technology is expected to mitigate this challenge by streamlining nursing work, while also improving quality of care and productivity. ObjectivesThis study set out to examine how nurses and care workers work, the role of information technology (IT) in their work and what contradictions they face in their IT mediated work. DesignEthnographic study informed by six components of activity theory: subject, object, tool, rule, community and division of labor. SettingEight care units in two long-term care facilities in Australia. ParticipantsEleven staff from two long-term care facilities including registered nurses (n = 2), endorsed enrolled nurses (n = 5) and personal care workers (n = 4) participated in this study. MethodsParticipants were shadowed during morning shifts (6:30 am to 3:00 pm). A total of 24 morning shifts were observed over four months. Field notes were created based on observational data and informal interviews, in addition to document review. ResultsThrough the lens of activity theory, the work activity system of nurses and care workers in the long-term care facilities consisted of the subject (nurses and care workers), their object (resident care), tools used for work including IT, rules of work, community, and division of labor. These components interacted through work processes; therefore, a “process” component was added in the activity system. Special attention was given to the role of IT as the conduit of information in the work processes. Although IT helped track medication rounds, automated documentation and communication among the staff, it introduced contradictions. Seven contradictions involving IT were identified, including contradictions within the IT tool, between the IT tool and the object of work, between the subjects and documentation rules, between the work activity system using paper records and the system using IT, and between the activity system within the long-term care facility and the pharmacists’ work activity system outside the facility. ConclusionsActivity theory provided a theoretic framework to model the work activity system of nurses and care workers. Information technology played an important role in supporting information flow in this system, however it also caused contradictions.