Background Low-frequency ultrasonic debridement (LFUD) is a technology that uses sound waves conducted through saline mist to debride wound tissue. Whilst this technology purportedly reduces wound-healing times, the airborne mist generated is potentially problematic. Theoretically, the saline mist could carry an increased number of microbes into the surrounding environment, posing an infection control risk to the patient, clinician, and clinical environment. This research aimed to establish the degree and extent to which there is microbial spread during the use of, and following the use of, LFUD. The total number of colony forming units was identified for use of LFUD without the suction attachment (control) and with the suction attachment (intervention). Methods This was a prospective, observational study with repeated measures across each treatment (before, during, and after). Quota sampling in a 2 × 2 × 2 factorial design was undertaken so that half of the 24 treatments were conducted at each health service (Monash Health vs Peninsula Health), in different treatment environments (inpatient vs outpatient), and half were conducted with and without suction. The use of suction was not randomized but was determined at the treating clinician's discretion. Patients treated in the inpatient environment lay on their beds, whereas patients in the outpatient environment sat in a treatment chair. Results There was higher microbial count during treatment (P < .001) with a higher microbial count associated with lower ultrasound amplitude (P = .028), lower saline flow rate (P = .010), no suction attachment (P = > .001), and a larger wound area (P = .002). All were independently associated with greater microorganism aerosolization. There was no correlation between the type of handpiece selected, the presence of wound infection, and the treatment time or treatment environment. Conclusions This research has assisted in developing guidelines for cleaning of equipment and environments following treatment, as well as around the use of personal protective equipment required to protect the staff member and the patient during the use of LFUD. Additionally, recommendations have been made regarding the specific LFUD settings to reduce the risk of cross-infection to the clinic environment. These include selecting a higher ultrasound amplitude and saline flow rate as well as the use of suction where clinically possible. © 2016 Association for Professionals in Infection Control and Epidemiology, Inc.