AIM: The aim of this exploratory study was to determine whether the level of nursing teamwork is correlated to call light answering time in acute care hospital patient care units. Background: Teamwork has been shown to improve productivity. In this study, we examine the relationship between unit call light response time as a measure of productivity and the level of teamwork on the unit. METHOD: The Nursing Teamwork Survey was administered to nursing staff on 18 inpatient units in 3 hospitals. In addition to the overall teamwork score, the NTS has 5 subscales. Call light response times were collected from electronic systems which measures the time it takes for nursing staff on a given unit to respond to patient call lights. RESULTS: There was no significant relationship between call light response time and teamwork overall or on the five subscales. Shared mental models, which comprise the conceptual understanding of the roles and responsibilities of each team member, however was moderately correlated with call-light answering times. CONCLUSIONS: It is logical that shared mental models would be associated with call light response time since a common problem in patient units is the "it's not my job syndrome" where nursing staff do not answer call lights for patients assigned to someone else. More research with a larger number of patient units is needed to validate these findings.