OnabotulinumtoxinA treatment for spasticity is dependent on numerous factors and varies according to selected treatment goals.Examine real-world onabotulinumtoxinA treatment utilization and effectiveness in patients with upper limb spasticity over 2 years from the Adult Spasticity International Registry (ASPIRE) study.Multicenter, prospective, observational registry (NCT01930786).54 international clinical sites in North America, Europe, and Asia.Adults (naïve or non-naïve to botulinum toxins for spasticity) with upper limb focal spasticity related to upper motor neuron syndrome across multiple etiologies.OnabotulinumtoxinA administered at clinician's discretion.OnabotulinumtoxinA utilization, clinician and patient satisfaction.484 patients received ≥1 treatment of onabotulinumtoxinA for upper limb spasticity. Patients were on average 55.1 years old, 50.8% male, predominantly Caucasian (72.3%), and 38.6% were naïve to botulinum toxins. Stroke was the most frequently reported underlying etiology (74.0%). Most patients (81.2%) had moderate to severe spasticity at baseline. The most commonly treated upper limb clinical presentation was clenched fist (79.1% of patients). Across all presentations, onabotulinumtoxinA doses ranged between 5-600 U. Electromyography (EMG) was most often utilized to localize muscles (≥57.0% of treatment sessions). Clinicians (92.9% of treatment sessions) and patients (85.7%) reported being extremely satisfied/satisfied that treatment helped manage spasticity, and clinicians (98.6%) and patients (92.2%) would definitely/probably continue onabotulinumtoxinA treatment. 179 patients (37.0%) reported 563 adverse events (AEs); 15 AEs in 14 patients (2.9%) were considered treatment-related. 69 patients (14.3%) reported 137 serious AEs; 3 serious AEs in 2 patients (0.4%) were considered treatment-related. No new safety signals were identified.ASPIRE captured the real-world individualized nature of onabotulinumtoxinA utilization for upper limb spasticity over 2 years, with consistently high clinician- and patient-reported satisfaction. Data in this primary analysis will guide clinical use of onabotulinumtoxinA, as well as provide insights to improve educational programs on spasticity management. This article is protected by copyright. All rights reserved.