Background: Teamwork skills are essential to the quality of care and patient safety; nevertheless, team training is limited in Bachelor of Nursing degree programs in Norway. Objectives: The objective of this study was to explore the impact of implementing a TeamSTEPPS® team training intervention on Bachelor of Nursing students' attitudes toward teamwork in health care. Design: A longitudinal quasi-experimental design with pre- and posttests was used. Settings: One intervention group and one control group were recruited from two campuses at a Norwegian university offering a Bachelor of Nursing degree. Participants: Subjects were recruited from a population of 423 students. Methods: For 26 months, the intervention group was exposed to the TeamSTEPPS® team training program with various learning activities to enhance teamwork skills. The intervention group and the control group responded to the Norwegian version of the TeamSTEPPS® Teamwork Attitude Questionnaire (T-TAQ) before the intervention (T0), after ten months (T1), and after 24 months (T2). The students participated in survey T0 and T1 was defined as Sample 1 and students participated in survey T0 and T2 was defined as Sample 2 The data were analyzed with parametric and nonparametric statistics. Results: At T0 there was a significant difference between the intervention and control group. The intervention group showed a significant positive change in the Total T-TAQ score from T0 to T1 and from T0 to T2. The change in mean score differed significantly between the intervention and control group in favor of the intervention group. Conclusions: This study showed that a team training program improved Bachelor of Nursing students' attitudes toward teamwork. Therefore, we recommend that the TeamSTEPPS® team training program be implemented in Bachelor of Nursing programs to facilitate a culture of teamwork.