EXHIBIT 5.1

                                  May 29, 2002

Bel Fuse Inc.
198 Van Vorst Street
Jersey City, NJ 07302


Gentlemen:

You have requested our opinion in connection with the registration with the
Securities and Exchange Commission under the Securities Act of 1933, as amended
(the "Act"), of 1,000,000 shares of Class B Common Stock, par value $.10 per
share ("Class B Common Stock"), of Bel Fuse Inc. (the "Company") on a
registration statement on Form S-8 (the "Registration Statement'). The shares of
Common Stock to which the Registration Statement relates are issuable pursuant
to the Company's 2002 Equity Compensation Program (the "Plan").

We have examined and relied upon originals or copies, authenticated or certified
to our satisfaction, of all such corporate records of the Company,
communications or certifications of public officials, certificates of officers,
directors and representatives of the Company, and such other documents as we
have deemed relevant and necessary as the basis of the opinions expressed
herein. In making such examination, we have assumed the genuineness of all
signatures, the authenticity of all documents tendered to us as originals, and
the conformity to original documents of all documents submitted to us as
certified or photostatic copies.

Based upon the foregoing and relying upon statements of fact contained in the
documents which we have examined, we are of the opinion that the shares of Class
B Common Stock offered by the Company pursuant to the Plan, when registered
pursuant to the Act and paid for in full by the participants in accordance with
the Plan, will be, when issued, legally issued, fully paid and non-assessable.

We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and any amendment thereto.

Very truly yours,

LOWENSTEIN SANDLER PC


By: /s/ LAURA R. KUNTZ
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    Laura R. Kuntz