(1) Background: São Paulo, Brazil, exhibits high mortality rates from pediatric solid tumors. This study analyzed the survival trends of patients aged 0-19 diagnosed with the state's five most prevalent solid tumors between 2000-2022. (2) Methods: An epidemiological, descriptive study utilized data from the Oncocentro Foundation of São Paulo, classified according to the International Classification of Childhood Cancer. The time between the first consultation and diagnosis, between diagnosis and treatment initiation, and patient survival were assessed using the Pe-to-Peto test. (3) Results: Analysis involved 11,067 cases: 53.5% male, with 89.6% diagnosed via microscopic confirmation. Tumor distribution comprised 34.3% central nervous system, 21.1% bone, 18.6% soft tissue, 14.2% germ cell, and 11.9% retinoblastomas. Main treatments included surgery with chemotherapy (26.5%), surgery alone (20.5%), and chemotherapy alone (15.6%). The average time between consultation and diagnosis was 22.94 ± 69.93 days, significant for treatments and recurrences, except for germ cell tumors (p=0.0178). The time between diagnosis and treatment was 25.46 ± 39.71 days, not significant for germ cell tumor treatments (p=0.0793). (4) Conclusions: Survival curves varied among neoplasm groups, with patients experiencing delays beyond recommended times, despite advanced healthcare services in the state.