Studies demonstrated that support during labor and birth has a positive impact on childbirth outcomes, and that women reported they received little supportive care from nurses during parturition. This study piloted a work sampling method that was adapted to determine the proportion of time the average intrapartum nurse at a Toronto teaching hospital spends in supportive care activities. Supportive care was operationally defined within four categories of activities: emotional support, physical comfort measures, instruction/information, and advocacy. Work sampling was an effective method of measuring support as a specific aspect of direct intrapartum care. The proportion of time that nurses spent in supportive versus all other activities was 9.9 percent (95% confidence interval 7.5% and 12%), based on a sample of 616 random observations of 18 nurses. Findings are discussed in terms of the social and political factors that affect the meaning and value of the supportive activities of work by obstetric nurses.