INTRODUCTION: Janitorial service work is typically labor-intensive and demands heavy workloads. Despite the exposures to numerous occupational risks and resulting high injury occurrences, there is a lack of research addressing the burden of injuries and associated risk factors in this population. The aims of this study were to: 1) Determine the injury incidence and severity of injury occurrences in janitors and identify associated risk factors; 2) Analyze the effects of workload exposures on injury occurrence. Our central hypothesis was that, based on the varying occupational exposures, injury incidence and severity in this population is high, and that an increased workload contributes to these elevated injury occurrences. Additionally, conversations with local janitors highlighted a need for education on workers’ rights and responsibilities for reporting injuries; thus, a final aim of this study was to: 3) Evaluate and improve janitors’ knowledge of workers’ rights and responsibilities for assessing and reporting work-related injuries through an intervention. METHODS: A prospective cohort study was conducted to collect data among janitors in the SEIU Local 26 from May 1, 2016 to April 30, 2017. Injury- and exposure- related data were collected through specially designed questionnaires while workload data were collected using both fitness tracker bracelets and questionnaires. Upon completion of this study, the varying workloads and other exposures experienced by janitors were analyzed to determine their potential relations to injury occurrences. Additionally, an intervention study was implemented and a potential change in workers’ perceived barriers for reporting injuries was identified between the two six-month reporting periods. RESULTS: A total of 390 janitors participated in the study (response rate = 33%); among them, 34% reported experiencing at least one injury. The most common injury reported was pain (66%), and 16% of injury cases resulted in hospital admittance. The most common body parts injured involved primarily the back and lower extremities. There was a significant increase in risk based on age, ethnicity, shift start time and depression. Of the janitors, 37% reported an increase in workload over the study period. Adjusted analyses indicated a significant relation between change in workload and duration of sleep and occupational injury. Through analyses of workload and injury, stratified by sleep quality, there was a significant association among those with sleep disturbances. At baseline, in the intervention and non-intervention groups, approximately 25% reported perceived barriers to reporting an injury to their employer. Reported barriers included “fear,” “reporting takes too long,” “being unsure of the reporting process,” and an “understanding that injuries are a part of the job.” At follow-up, among the intervention group, there was an important reduction (24% to 12%) in having perceived barriers for “reporting an injury to your employer.” CONCLUSIONS: Knowledge of specific risk and protective factors are extremely important. They serve as a basis for further in-depth studies. In the long term, these study findings will serve as a basis for development of interventions that can be used to generate policies and interventions for safer working environments among janitors.