SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

Report of Foreign Issuer

Pursuant to Rule 13a-16 or 15d-16 of

the Securities Exchange Act of 1934

For the month of ~~April~~September, 2006

CIBA SPECIALTY CHEMICALS HOLDING INC.

(Exact name of Registrant as specified in its charter)

Klybeckstrasse 141

4002 Basel

Switzerland

(Address of principal executive offices)

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

Form 20-F x þ Form 40-F o

(Indicate by check mark whether ~~the registrant~~ by furnishing the information contained in this ~~form~~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 xþ

(If " “Yes" ” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2 (b))

CIBA SPECIALTY CHEMICALS HOLDING INC.

On ~~April~~ 27September 13, 2006, Ciba Specialty Chemicals Holding Inc., a stock corporation, organized under the laws of Switzerland, issued a News Release ~~regarding~~announcing a cash tender offer for its ~~three~~Swiss ~~month~~Franc ~~(or~~denominated ~~first~~bonds ~~quarter)~~maturing ~~results 2006~~2008. A copy of ~~this~~ the News Release is attached ~~hereto~~ as Exhibit 99.1 and incorporated by reference herein.

2EXHIBIT LIST

EXHIBIT INDEX


Exhibit		Description

99.1		News Release, dated September 13, 2006 of Ciba Specialty Chemical Holding Inc.

Exhibit	Description
99.1	News Release: Three Month Results 2006, dated April 27, 2006

SIGNATURES

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

Ciba Specialty Chemicals Holding Inc.(Registrant)


		Ciba Specialty Chemicals Holding Inc.

		(Registrant)

Date September 13, 2006	By	/s/ Daniel Petitpierre	/s/ Max Dettwiler

		Daniel Petitpierre Head Corporate Law	Max Dettwiler Head Taxes, Corporate Law & Insurance

Date May 4, 2006	By	/s/ Oliver Strub	/s/ Max Dettwiler
		Oliver Strub	Max Dettwiler
		Head Corporate Law	Head Taxes,Corporate
			Law & Insurance

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