6-K

FORM 6-K

U.S. SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE

SECURITIES EXCHANGE ACT OF 1934

Dated August 27, 2009

Commission File Number 1-14878

GERDAU S.A.

(Exact Name as Specified in its Charter)

N/A

(Translation of Registrant’s Name)

Av. Farrapos 1811

Porto Alegre, Rio Grande do Sul - Brazil CEP 90220-005

(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Form 20-F  x Form 40-F  o

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): o

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): o

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of 1934.

Yes  o No  x

If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2(b):  Not applicable.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused the Report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date:  August 27, 2009

GERDAU S.A.
By:	/s/Osvaldo Burgos Schirmer
Name:		Osvaldo Burgos Schirmer
Title:		Chief Financial Officer

2

EXHIBIT INDEX

Exhibit	Description of Exhibit
99.1	Relevant Fact, August 27, 2009

3

EX-99.1

Exhibit 99.1

RELEVANT FACT

We announce that the Board of Directors Meeting of GERDAU S.A. held on August 26, 2009, resolved to authorize the Company to acquire shares of its own issue, in accordance with its bylaws and CVM Instructions 10/80 and 268/97.

Up to 500,000 preferred shares will be acquired, representing approximately 0.08% of the preferred shares free float, which totaled 622,428,013 shares on July 31, 2009, to be solely used for the Company’s Long-Term Incentive Program (Stock Option), by drawing cash from its existing profit reserves.

The authorization is effective as of August 27, 2009 up to September 10, 2009, inclusive, with the Board of Executive Officers responsible for establishing the number of shares and the opportune moment for each transaction.

The transactions will be carried out at the Brazilian Stock Exchange (Bovespa) at market price, acting as intermediary Credit Suisse Brasil S.A. Corretora de Títulos e Valores Mobiliários, Av. Brigadeiro Faria Lima, 3.064 - 13º Andar — São Paulo — SP.

Rio de Janeiro, August 27, 2009.

OSVALDO BURGOS SCHIRMER

Vice President

Investor Relations Officer