Objective To examine trends in fireworks-related injuries (FRI) before and after enactment of an ordinance to limit access in the City and County of Honolulu (the island of Oahu).

Methods Surveillance of FRI treated in all emergency departments in the state, for 18 new year’s periods (31 December through 1 January) from 2004 to 2021. Prelaw (2004 to 2011) and postlaw (2012 to 2021) number of FRI were compared, by patient age and county.

Results The average annual number of FRI for all ages decreased significantly in Oahu, from 74 during the prelaw period to 27 during the postlaw period (p<0.01), but not in the remaining neighbour islands (p=0.07). Decreases were particularly evident for Oahu paediatric patients (under 18 years), among whom FRI declined from 42 to 10 per year (p<0.01). FRI were approximately halved for older Oahu patients and neighbour island paediatric patients.

Conclusions Legislation requiring permits for a specified number and type of fireworks, and limiting access to persons 18 years and older was associated with significant decreases in FRI in the City and County of Honolulu.