This pilot study investigated the feasibility of using functional magnetic resonance imaging (fMRI) as a physiological marker of brain plasticity before and after an intensive body‐weight‐supported treadmill training (BWSTT) program in children with cerebral palsy (CP). Six ambulatory children (four males, two females; mean age 10y 6mo, age range 6–14y) with spastic CP (four hemiplegia, two asymmetric diplegia, all Gross Motor Function Classification System Level I) received BWSTT twice daily for 2 weeks. All children tolerated therapy; only one therapy session was aborted due to fatigue. With training, over ground mean walking speed increased from 1.47 to 1.66m/s (p=0.035). There was no change in distance walked for 6 minutes (pre‐: 451m; post‐: 458m;p 0.851). In three children, reliable fMRIs were taken of cortical activation pre‐ and post‐intervention. Post‐intervention increases in cortical activation during ankle dorsiflexion were observed in all three children. This study demonstrates that children with CP between 6 and 14 years of age can tolerate intensive locomotor training and, with appropriate modifications, can complete an fMRI series. This study supports further studies designed to investigate training‐dependent plasticity in children with CP.