Background Australia is yet to see widespread fentanyl-contaminated heroin, despite the established presence of fentanyl in other countries. International mortality trends alongside a local cluster of fentanyl-related deaths prompted interest in developing methods to monitor for fentanyl and other potentially harmful novel psychoactive substances (NPS) in Australia. Methods We tested novel methods to monitor for fentanyl and other NPS. From 2017-2021, clients from supervised injecting facilities (SIFs) in Melbourne and Sydney, Australia, contributed urine screens (UDS) with BTNX Rapid Response™ fentanyl test strips (FTS) paired with surveys, and injecting equipment associated with opioid overdoses for laboratory analysis. A single site piloted drug checking using FTS with laboratory confirmation. Two workshops were conducted with SIF staff, content experts and people with lived experience to determine how results can inform practices within SIFs. Results Of the 911 UDS with FTS conducted, less than 1% (n=8) yielded positive results that were not explained by self-reported pharmaceutical fentanyl use, with two laboratory confirmed fentanyl positive results. Injecting equipment from 59 overdoses was tested and neither fentanyl nor other NPS were identified. Drug checking with FTS (n=34) indicated the presence of fentanyl on three tests. Two specimens were subsequently sent for laboratory testing and classified as false positives as the presence of fentanyl was not confirmed. Workshop participants (n=21) felt routine monitoring with FTS currently had limited value. A process for using pre-defined signals to trigger surveillance was developed. Conclusion The high false positive rates with FTS, relative to the small number of positive results and potential for them to undermine confidence in FTS emphasised the need for confirmatory testing. The role of routine surveillance was unclear within the current low-fentanyl context, however, a process was developed to upscale testing should signals of increased fentanyl prevalence in the Australian heroin market emerge.