Exhibit 5.1

                   [Letterhead of Gibson, Dunn & Crutcher LLP]

                                  June 24, 2002

K-SWISS Inc.
31248 Oak Crest Drive
Westlake Village, California 91361

     Re:  K-SWISS Inc. Registration Statement on Form S-8

     Ladies and Gentlemen:


     We have acted as counsel to K-Swiss Inc., a Delaware corporation (the
"Company"), in connection with the preparation of a Registration Statement on
Form S-8 to be filed with the Securities and Exchange Commission (the
"Registration Statement") with respect to the registration under the Securities
Act of 1933, as amended, of 600,000 shares of Class A Common Stock, $.01 par
value (the "Shares"), of the Company (the "Common Stock"), subject to issuance
by the Company upon exercise of options granted and to be granted under the
Company's 1999 Stock Incentive Plan, as amended, in the form filed as Exhibit
4.1 to the Registrant's Statement (the "Plan").

     We have examined the originals or certified copies of such corporate
records, certificates of officers of the Company and/or public officials and
such other documents and have made such other factual and legal investigations
as we have deemed relevant and necessary as the basis for the opinions set forth
below. In such examination, we have assumed the genuineness of all signatures,
the authenticity of all documents submitted to us as originals, the conformity
to original documents of all documents submitted to us as conformed or
photostatic copies and the authenticity of the originals of such copies.

     Based on our examination mentioned above, subject to the assumptions stated
above and relying on the statements of fact contained in the documents we have
examined, we are of the opinion (i) the issuance by the Company of the Shares
has been duly authorized and (ii) when issued in accordance with the terms of
the Plan, the Shares will be duly and validly issued, fully paid and
non-assessable shares of Common Stock.

     We are admitted to practice in the State of California, and are not
admitted to practice in the State of Delaware. However, for the limited purposes
of our opinion set forth above, we are generally familiar with the General
Corporation Law of the State of Delaware (the "DGCL") as presently in effect and
have made such inquiries as we consider necessary to render this opinion with
respect to a Delaware corporation. This opinion letter is limited to the laws of
the State of California and, to the limited extent set forth above, the DGCL, as
such laws presently exist and to the facts as they presently exist. We express
no opinion with respect to the effect or applicability of the laws of any other
jurisdiction. We assume no obligation to revise or supplement this opinion
letter should the laws of such jurisdictions be changed after the date hereof by
legislative action, judicial decision or otherwise.

     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement. In giving this consent, we do not admit that we are
within the category of persons whose consent is required under Section 7 of the
Securities Act or the General Rules and Regulations of the Securities and
Exchange Commission.

                                        Very truly yours,

                                        /s/ GIBSON, DUNN & CRUTCHER LLP
                                        -------------------------------

                                        GIBSON, DUNN & CRUTCHER LLP