Purpose The purpose of this report is to review our experience with talonavicular joint arthrodesis for the treatment of severe valgus foot deformities in older children and adolescents with cerebral palsy (CP). Methods The clinical, radiographic, and gait parameters results after talonavicular joint arthrodesis were retrospectively reviewed in 32 patients (59 feet) with valgus deformities of the foot. The surgery was performed as part of multiple simultaneous surgeries for the treatment of gait disorders. The mean age of the patients was 13.9 years (range 9-20 years) and the mean follow-up was 40 months (range 18.3-66.7 months). Results The clinical and radiographic measurements improved significantly (P = 0.000). There were no significant changes in gait parameters. Symptoms were relieved in most patients with symptomatic preoperative feet. The most frequent complication was pseudoarthrosis, which occurred in seven feet. We found a high rate of satisfaction of patients (or parents) and most of them recommended the procedure to other patients with the same condition. Conclusion Talonavicular joint arthrodesis is a reliable technique that provides both functionally and cosmetically good results with a low rate of complications in the treatment of severe pes planus valgus in older children and adolescents with CP. Careful examination should rule out concomitant ankle valgus deformities. A stable fixation of the arthrodesis is recommended.