ObjectiveTo compare physical activity (PA) levels between individuals with femoroacetabular impingement syndrome (FAIS) and uninjured controls and determine correlates of moderate to vigorous physical activity (MVPA). DesignCross-sectional, comparative study. SettingUniversity laboratory. ParticipantsA total number of 25 individuals with FAIS (15 female; age, 31.0±9.2 years; symptom duration, 4.7±7.1 years) and 14 uninjured controls (9 female; age, 28.0±9.1 years) (N=39). InterventionsNot applicable. Main Outcome MeasuresAll individuals wore an accelerometer around the waist during waking hours for 7 days. We compared demographic, clinical data, and PA levels between groups using independent samples t tests and compared the proportions of those meeting the PA guideline cutoff (150min/wk) using a chi-square test. Additionally, we examined correlates of mean daily MVPA using linear regression in both groups. ResultsIndividuals with FAIS spent less time in MVPA (controls, 52.1±25.6min/d; FAIS, 26.9±19.1min/d; P=.001) and took fewer steps (controls, 8428±2931 steps/d; FAIS, 6449±2527 steps/d; P=.033) than uninjured controls. A lower proportion of individuals with FAIS met the PA cutoff (40.0%) compared with uninjured controls (78.6%; P=.020). Higher body mass index (BMI) values and lower (worse) Hip Disability and Osteoarthritis Outcome Score (HOOS)–Quality of Life subscale scores were associated with lower mean daily MVPA in those with FAIS (R2=21.2%, P=.021; R2=22.0%, P=.018; respectively) but not in uninjured controls. ConclusionsIndividuals with FAIS spent less time in daily MVPA, took fewer daily steps, and met recommended PA guideline cutoffs at lower proportions compared with uninjured controls. Higher BMI and lower HOOS-Quality of Life scores were associated with lower mean daily MVPA. Interventions should be developed for individuals with FAIS to increase PA engagement to potentially lessen the risk of future comorbidities associated with decreased PA and increased BMI.