1. Economic-Financial Office and Investor Relations Office 2Q11 Results Conference Call August / 2011

2. 2 This presentation may contain forward-looking statements referring to SABESP’s business outlook. operating and financial results estimates. and growth prospects. These are only projections. and as such. they are exclusively based on SABESP’s management expectation in relation to the future of business and its continuous access to capital to finance the Company’s business plan. These forward-looking statements largely depend on changes in market conditions. governmental rules. industry performance and the Brazilian economy. amongst other factors. in addition to risks exhibited in disclosure documents filed by SABESP. Therefore. they are subject to changes without prior notice. Notice

3. Billed Volume 3 Total billed water and sewage volume, including wholesale (million m³ ) 3.0% 3.4% 2.7% 1,703.1 1,753.8 3.1% 3.7% 2.7% 847.9 874.5

4. Financial Highlights 4

5. 5 Costs and Expenses (R$ million) % Net Revenue in 2Q10 17.4%23.3%1.4% 12.1%5.7%1.6%6.5%3.4%0.5% % Net Revenue in 2Q11 17.6%20.8%1.5% 9.9%6.5%6.7%7.5%1.8%0.4% 18.5% 4.1% 7.1% 15.8% (15.3%) 16.6% 336.1% (12.8%) (44.7%) (8.3%) 4.2% Costs and expenses in 2Q10: R$ 1,668.6 Costs and expenses in 2Q11: R$ 1,739.3

6. Net Income 7 Main variations on Net Income Exchange variationResult, net of financialsFinancial expenses, netIncome tax and social contribution Monetary variation 319.5 67.3 (70.7) 46.8 165.6 (48.9) 479.6 604.0 (18.4) (164.5) (76.3) (25.3) 74.2 647.4 (213.3) (6.0) (22.7) 189.1% (5.8)% (51.5)% (23.9)% (7.9)% 15.5% 134.9% (44.5)% (1.2)% (4.7)%

7. Annual Adjustment Calculation Index Part A Part B Annual Tariff Adjustment vs. Inflation (%) Inflation (IPCA) X Manageble Costs Adjustment defined by ARSESP Adjustment according to the calculation method 7 Full repass of manageble costs Including:  Electric power  Treatment supplies  Taxes  Costs for the use of water resources Annual Tariff Adjustment

8. www.sabesp.com.br IR Contacts Mario Azevedo de Arruda Sampaio Angela Beatriz Airoldi maasampaio@sabesp.com.br abairoldi@sabesp.com.br (55 11) 3388-8664 (55 11) 3388-8793