Objective: To analyze the expenses of hospitalizations for ambulatory care sensitive conditions in the Health Regional Offices of the State of São Paulo. Methods: An ecological, retrospective cohort, with analysis of hospital admissions for ambulatory care sensitive conditions in the state of São Paulo, from 2014 to 2018, compiled by the Hospital Information System. Data were extracted using the Tabwin application and analyzed using descriptive statistics. Results: There was a 14.49% reduction in the amount spent on hospitalizations for ambulatory care sensitive conditions. There were reductions in the frequency of hospitalizations (−1.26) and hospital stay (−0.54), and an increase in the occurrence of deaths (8.02). The Regional Offices of Barretos, Taubaté and Araraquara showed an increase in expenses in the period, by 37.86%, 15.38% and 3.78%, respectively, while all other Regional Offices showed a reduction; in that, the most significant were in Bauru (−31.90%), São João da Boa Vista (−26.18%), Presidente Prudente (−21.00%) and São Paulo (−19.17%). The value of hospitalizations for ambulatory care sensitive conditions showed a strong and positive correlation with the variables frequency and hospital stay. Conclusion: The results pointed to a difference in the amounts spent on hospitalizations for ambulatory care sensitive conditions in the Regional Offices, although there was no difference in the frequency and duration of these hospitalizations. The expansion of Primary Health Care resources is a possible element for reducing the frequency and spending on hospitalizations for ambulatory care sensitive conditions; nonetheless, it is necessary to consider other factors, such as social determinants and the organization of health services.