Background <p>Simulation exercises are increasingly being used in undergraduate nursing education. The aim of this study was to identify, describe and discuss the factors that facilitate the successful implementation of simulation exercises for the transition to clinical practice in primary healthcare settings experienced by nursing students.</p> Methods <p>Seven focus group interviews were conducted with a total of 35 undergraduate nursing students from two university campuses in Norway. There were three focus groups with first-year students, two focus groups with second-year students and two focus groups with third-year students. The interviews were analysed using reflexive thematic analysis.</p> Results <p>The analysis identified four main themes, each including essential factors for successful implementation of simulation exercises: (1) feeling secure (2), experiencing realism (3), learning in different roles and (4) reflecting together.</p> Conclusions <p>The findings outline key factors experienced by the participants that may contribute to successful simulations. These insights may guide future implementation of simulation exercises in undergraduate nursing education, specifically for the transition to clinical practice in primary healthcare settings.</p> Clinical trial number <p>Not applicable.</p>