BACKGROUND:There are limited evidence of instrumented measures of gait and balance to determine the functional effects of botulinum toxin injections (BoNT-A) in spasticity after stroke. OBJECTIVE:To evaluate the functional changes in gait and balance following upper limb and lower limb BoNT-A in persons with stroke. METHODS:A pre-post prospective study of 35 stroke patients with upper and/or lower limb spasticity after focal treatment with BoNT-A. Assessments were at baseline (T0), 6-weeks (T1) and 12-weeks (T2), using validated subjective and objective physical activity measures. RESULTS:After BoNT-A injections, significant improvements in most measures of impairments, activity and participation domains were found at T1 (p < 0.05, effect sizes (r) = 0.5-0.9). There was a significant increase in low intensity physical activity (at T1) and sedentary time reductions at both follow-up periods. Instrumented gait/balance measures showed a significant increase in cadence and turn velocity, but no changes in sway measures were found using posturography. Improvements in most outcome measures were maintained at 12-weeks. CONCLUSION:BONT-A improved scores in most clinical measures but only in some of the objective gait/balance and physical activity measures. Further robust studies should utilize a larger sample size to better determine the benefits of BoNT-A for stroke-related spasticity.