The aim of the study was to identify oral baclofen dosing variability at steady state based on weight and Gross Motor Function Classification System level using a retrospective cross-sectional study design. The medical records of 500 pediatric aged patients (age 1-21 yrs) were reviewed to obtain 144 pediatric patients who met inclusion criteria. One-way analysis of variance tests revealed increasing mean doses in baclofen (in milligram per kilogram) with higher Gross Motor Function Classification System levels (P = 0.001). Post hoc Tukey analysis showed patients with higher ambulatory ability (Gross Motor Function Classification System I-II) received a lower total daily dosage than did patients with less ambulatory ability (Gross Motor Function Classification System III-V). A moderate correlation was observed with increasing oral baclofen dose as weight increased (r = 0.43, P < 0.0001). Because of the variability in dosing between Gross Motor Function Classification System levels, prescribing oral baclofen for pediatric patients with cerebral palsy may not follow the traditional model of weight-based dosing seen in other pediatric conditions.