The study aimed at identifying factors limiting the Tietê and Paraná valleys economic growth. Specifically, it analyzed the importance of the capital stocks for economic growth of these and the other counties in São Paulo State. Nine factors were generated by Principal Components Method to represent the capital stocks and were denominated: Human Capital I; Physical Capital; Social Capital I; Human Capital II; Financial Capital I; Social Capital II; Natural Capital I; Financial Capital II; Natural Capital II. The percentage of the total variance explained by each stock of capital was 19.5% (human); 8.3% (social); 6.0% (financial); 5.9% (physical), and 4.8% (natural). The study indicated that there are two different groups concerning the income index in the Estate of São Paulo and they must not be considered together. Linear regressions were adjusted with these factors explaining the income index that is part of the Human Development Index (HDI). Social Capital I (Associationism) was not in the solution in any group. The variable created to differentiate municipalities located close the rivers (dummy) did not enter the equations. This result suggests no difference between such municipalities and the others of the State, in the same income group, concerning the role oft the stocks of capital.