Background Children <8 years who were prematurely transitioned from a booster seat to a seat belt (booster transition) have a higher road traffic injury risk. This qualitative research aimed to explore the parent’s decision-making on booster transition and to identify factors that influence parents’ decisions.

Methods We conducted 20 semi-structured interviews virtually with parents/guardians from Columbus, Ohio. All individual interviews were audio-recorded and transcribed verbatim. Grounded theory with initial coding and focused coding was used to analyze data. All transcribed data were imported into NVivo and coded by two researchers followed by group discussions to identify themes and resolve discrepancies.

Results We identified eight themes that were related to parents’ decision-making on booster transition. Internet was the most common source for parents seeking information regarding booster seats. Many participants reported the information they found was useful and trustworthy, though some participants talked about the challenges of finding accurate information and deciphering information regarding when they should stop using booster seats.

Conclusion Our findings have important implications for developing interventions to improve booster seat use, highlighting the necessity of redesigning educational materials regarding the proper booster transition.

Learning outcomes Eight themes associated with booster transition were identified. Three of them are child-related: (1) age and physical size; (2) maturity; and (3) motivation and willingness. The remaining five are parent-related: (1) safety as a priority; (2) convenience of non-use; (3) awareness and knowledge about the law; (4) influence from others (spouse, pediatricians, et al.,); (5) decision-making approaches.