<page>

Exhibit 5.1

                             RICHARDSON & PATEL LLP
                              10900 WILSHIRE BLVD.
                                    SUITE 500
                          LOS ANGELES, CALIFORNIA 90024
                               TEL (310) 208-1182
                               FAX (310) 208-1154


                                  May 21, 2008


Universal Detection Technology
9595 Wilshire Blvd., Suite 700
Beverly Hills, California 90212
(310) 248-3655

         Re:      2008 - EQUITY INCENTIVE PLAN II

Ladies and Gentlemen:

         We have acted as counsel to Universal Detection Technology, a
California corporation (the "Company"), in connection with the preparation of
the filing with the Securities and Exchange Commission under the Securities Act
of 1933 of the Company's Post Effective Amendment No. 1 to the Registration
Statement on Form S-8 relating to 330,000,000 shares of the Company's common
stock (the "Shares") which may be issued pursuant to the Universal Detection
Technology 2008 - Equity Incentive Plan II (the "Plan"). This opinion letter is
being furnished to the Company in accordance with the requirements of Item
601(b)(5) of Regulation S-K of the Securities Act, and no opinion is expressed
herein as to any matter, other than as to the validity of the Shares.

         In connection with that registration, we have reviewed the proceedings
of the Board of Directors of the Company relating to the registration and
proposed issuance of the Shares, the Certificate of Incorporation of the Company
and all amendments thereto, the Bylaws of the Company and all amendments
thereto, and such other documents and matters as we have deemed necessary to the
rendering of the following opinion.

         As to the facts on which this opinion is based, we have relied upon
certificates of public officials and certificates and written statements of
officers and representatives of the Company.

         In our examination, we have assumed the genuineness of all signatures,
the authenticity of all documents submitted to us as original documents, the
conformity to original documents of all documents submitted to us as copies and
the legal capacity of natural persons.




<page>

         The opinion expressed herein is limited to the California General
Corporation Law including the applicable provisions of the California
Constitution and the reported judicial decisions interpreting such law, in each
case as currently in effect, and we express no opinion as to the effect of the
laws of any other jurisdiction. In addition, we have assumed that the
resolutions authorizing the Company to issue or deliver and sell the Common
Stock pursuant to the Plan and the applicable award agreements will be in full
force and effect at all times at which such shares of Common Stock are issued or
delivered or sold by the Company, and the Company will take no action
inconsistent with such resolutions.

         In rendering the opinion above, we have assumed that each award under
the Plan will be approved by the Board of Directors of the Company or an
authorized committee of the Board of Directors.

         Based upon that review, it is our opinion that the Shares, when issued
will be legally issued, fully paid, and nonassessable. We do not find it
necessary for the purposes of this opinion to cover, and accordingly we express
no opinion as to the application of the securities or blue sky laws of the
various states of the United States to the issuance and sale of the Shares.

         We assume no obligation to advise you of any changes in the foregoing
subsequent to the date hereof.

         We consent to the use of this opinion in the registration statement
filed with the Securities and Exchange Commission in connection with the
registration of the Shares and to the reference to our firm under the heading
"Interests of Named Experts and Counsel" in the registration statement. In
giving such consent, we do not thereby admit that we are included in the
category of persons whose consent is required under Section 7 of the Act or the
rules and regulations of the Securities and Exchange Commission promulgated
thereunder.


                                                RICHARDSON & PATEL LLP


                                                /S/ RICHARDSON & PATEL LLP