AIM: This paper examines how time is controlled and governed in operating rooms through interpersonal communication between nurses and doctors. BACKGROUND: Time is a valuable commodity in organizations with improvements often directed towards maximizing efficiencies. As a consequence, time can be a source of tension and interpersonal conflict as individuals compete for control of its use. METHODS: The data in this paper emanate from an ethnographic study that explored a range of communication practices in operating room nursing. Participants comprised 11 operating room nurses. Data were collected over two years in three different institutional settings and involved participant observation, interviews and the keeping of a personal diary. A deconstructive analysis of the data was undertaken. RESULTS: Results are discussed in terms of the practices, in which clinicians are engaged in, to govern and control their use of time. The four practices presented in this paper include; questioning judgment and timing, controlling speed, estimating surgeons' use of time and coping with different perceptions of time. CONCLUSIONS: Time and speed were hotly contested by nurses. They used their personal knowledge of individual surgeon's habits of time to govern and control practice. Nurses thought about surgeons in terms of time and developed commonly accepted understandings about the length of surgical procedures. They used this knowledge to manage the scheduling of operations in the departments and to control the workflow in individual operating rooms. Knowledge of individual surgeons was a source of power for operating room nurses. RELEVANCE TO CLINICAL PRACTICE: Nurses have more power in the operating room than might be imagined but they exercise this power in subtle ways. If operating rooms are to work effectively, the operating room team must understand each others' work better.