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Background Botulinum Toxin A (BoNT-A) treatment remains a widely used intervention in the management of hypertonia in cerebral palsy, yet the optimal timing and frequency of reinjection are frequently debated. 1 2 Emerging evidence highlights potential risks to muscle development with repeated dosing whilst service protocols often rely on fixed intervals or impairment-based criteria.3 Methods A longitudinal mixed-methods study within The Wolfson Neurodisability Service at GOSH examined functional outcome following lower limb BoNT-A over a 12-month period in a cohort of 64 ambulant children with cerebral palsy (mean age 7.4 y ±2.4). Outcomes were measured at baseline, 6-weeks; 6-months and 12-months throughout the ICF including, movement quality (QFM), and goal attainment (COPM). Reinjection rates, timing, and clinical reasoning were analysed alongside multilevel regression to assess predictors of outcome.Results Reinjection rates were low (37.5%); second doses occurred approximately 10 months post-initial injection (41.3 weeks ±4). Children receiving repeat injections typically presented with more complex profiles, including multilevel involvement and lower baseline function. Re-injection decisions were multifactorial and not consistently linked to goal non-attainment or recurrence of dynamic spasticity as measured by the Modified Tardieu Scale. Qualitative data highlighted broader influences on clinical reasoning, including anticipated therapy access and parental expectations. Multilevel regression identified reinjection as a confounding variable but not a significant predictor of outcome in any group. Functional gains post-reinjection were comparable to those achieved with a single dose, suggesting that repeat dosing may help some children reach expected levels of improvement rather than confer additional benefit.Interpretation These findings contribute to the ongoing debate around reinjection practices, indicating that more frequent BoNT-A dosing does not necessarily afford improved outcomes in activity and participation domains. Judicious use—particularly with longer intervals and individualised goals—may better support functional progress whilst minimising potential risks in ambulant children with cerebral palsy.Acknowledgement for support Children and Families from The Wolfson Neurodisabilty Movement Disorders Service and their community teams who generously gave their time and support.Acknowledgement for funding This work was supported by an NIHR CDRF award for the lead author (NIHR ICA-CDRF-2015-01-037) with support from NIHR GOSH BRC and GOSH ORCHID.References Katchburian L, Katchburian M. Lower-limb botulinum toxin A treatment in ambulant children with cerebral palsy. Paediatrics and Child Health 2024;34(8):290–9.Hastings-Ison T, Blackburn C, Graham HK, Rawicki B, Fahey M, Simpson P, Baker R. Optimum frequency of botulinum toxin injections to the gastrocsoleus in children with cerebral palsy-a randomised controlled trial. Developmental Medicine and Child Neurology 2014;56:27.Multani I, Manji J, Hastings-Ison T, Khot A, Graham K. Botulinum toxin in the management of children with cerebral palsy. Paediatr Drugs 2019;21(4):261–81.