OBJECTIVE: The purpose of this study was to describe adverse events (AEs) and dropouts (DOs) in randomized controlled trials of therapeutic exercise for hip osteoarthritis (HOA) and to identify whether Consolidated Standards of Reporting Trials (CONSORT) guidelines were followed. METHODS: The Cochrane Library, Embase, PubMed, and CINAHL databases were searched. Randomized controlled trials of therapeutic exercise for HOA published in English from January 1, 1980 to August 1, 2020 were included. Studies were excluded if other interventions were provided, if participants had previous hip arthroplasty, or if AEs and DOs for HOA participants were not reported separately. The internal validity of each study (Physiotherapy Evidence Database [PEDro] scoring) was assessed, participant and intervention characteristics were extracted, and the existence of a clear statement and reasons for AEs and DOs was reported. Descriptive statistics characterized results. Data heterogeneity prohibited the use of meta-analysis. RESULTS: Fourteen studies (mean PEDro score = 7.4; range = 6-10) from 10 countries were included, with 707 participants exercising. Exercise intensity was unspecified in 72.2% of exercise arms. Six studies (42.9%) included a statement of AEs, and 32 AEs were reported. All studies had a DO statement, but 29.0% of DOs occurred for unknown reasons. Six studies (42.9%) gave reasons for DOs that could be classified as AEs in 9 participants; 41 participants (5.8%) experienced exercise-related AEs. CONCLUSION: Reports of AEs were inconsistent, some DOs were potentially misclassified, and primary components of exercise interventions were frequently unreported. Despite these limitations, the overall low number of nonserious AEs suggests that the exercise-related risk of harm is minimal for individuals with HOA. IMPACT: Understanding the risk of harm associated with exercise for HOA can better inform safe dosing of exercise, clinical implementation, and replicability. Informative, consistent reporting of AEs, DOs, and exercise is needed. Greater use of the CONSORT harms-reporting checklist is warranted.