Pes valgus is a pathological condition which occurs in up to 25% of patients with cerebral palsy. Its correction in early age is essential to prevent progression of the deformity and to optimize the patient's function. In younger patients arthroereisis can be considered as a treatment that fills the void between orthotics and arthrodesis. We treated 15 patients (27 feet) with intra- or extra-sinus tarsi arthroereisis. Concomitant Achilles tendon lengthening was performed in 12 feet. Results were good in 19 feet and poor in 8. Even though arthoereisis presents some complications, it can be considered a useful treatment to delay or avoid a Grice subtalar arthrodesis in flexible pes valgus due to cerebral palsy.