Abstract: Background: Understanding cumulative exposure to temperatures is important for assessing vaccine viability. Cold chain monitoring systems in Australia do not monitor cumulative exposures for individual vaccines from point of manufacture to administration. Remote Australia poses additional challenges to vaccine integrity due to vast geographical distances, extreme environmental temperatures, disjointed supply routes and interruptions to power supply. Aim: This study aims to quantify individual vaccine exposure to temperatures outside the cold-chain recommended temperature range (2-8°C) from dispatch to the point of administration. Method: Sixty electronic temperature monitors were attached to individual vaccines dispatched from a remote hospital pharmacy department to remote clinics between November 2017 and March 2018. Monitors were returned with vaccine administration details and cumulative exposures to temperatures outside of the recommended range (2-8°C) were assessed. Results: Monitored vaccines were distributed to 13 different clinics, travelling an average of 243 km (range 2.9 km to 521 km), all in non-refrigerated vehicles and often on dirt roads. Thirty one (51.7%) temperature monitors were returned, 17 (28.3%) of these were accompanied with complete administration records. All 31 monitors that were returned recorded temperature excursions above 8°C during packing at the pharmacy department, transportation to and/or during storage at the clinic. The average peak temperature exposure was 18.1°C (range 9.4°C to 27.3°C) and average cumulative time above 8°C was approximately 19 hours. Thirty (96.8%) of the cumulative temperature exposures were acceptable according to the local protocol; one episode of freezing was recorded by the monitor that was not identified by the clinic’s monitoring system. Conclusion: Temperature excursions outside of the recommended cold chain occurred frequently, however most cumulative temperatures were acceptable according to the local protocol. This study did not capture data on vaccine cold chain prior to arrival at the pharmacy department. Future studies should include cumulative temperature data from vaccine manufacture to the point of administration to accurately quantify vaccine viability. Electronic temperature monitors are useful in identifying areas for improving the cold chain and should be considered with regular audits to test the performance of cold chain management systems.