Background. The step activity monitor (SAM) quantifies steps taken in the home and community by patient populations. Although the SAM has been used to study individuals after stroke, adherence to the use of SAMs has not been addressed. Participants' adherence to wearing the monitor is critical for obtaining accurate assessments. Objective. The purpose of this study was to determine the rate of and predictors for inferred adherence to the use of the SAM after stroke. Design. A cross-sectional design was used. Methods. Community-dwelling individuals (n=408) 2 months after stroke with moderate-to-severe gait impairment (gait speed of <0.8 m/s) were studied. Step activity was assessed for 2 days with the SAM. Inferred adherence was established in 3 periods: 6:00 am to 12:00 pm, 12:01 pm to 6:00 pm, and 6:01 pm to 12:00 am. Adherence was defined as activity recorded in all 3 periods. The percentage of participant adherence for the first day, second day, both days, and either day was calculated. Demographic and clinical characteristics of adherers and nonadherers were compared. Independent adherence predictors were identified by means of stepwise logistic regression. Results. Inferred adherence rates for the first day, second day, both days, and either day were 68%, 61%, 53%, and 76%, respectively. Upper and lower extremity impairment, balance control, and endurance were significantly different between adherers and nonadherers. On the other hand, older age, greater balance self-efficacy, and better walking endurance were significant predictors of adherence. Limitations. Participants were individuals with subacute stroke. Therefore, the findings of this study may not be generalized to individuals during the acute and chronic phases of stroke recovery. Conclusions. Strategies to improve adherence are needed when collecting data for more than 1 day and in samples with younger individuals and those with low levels of balance self-efficacy and walking endurance.