Exhibit 5
   
                    [GEOTEK COMMUNICATIONS, INC. LETTERHEAD]




                                                     October 16, 1995 




Geotek Communications, Inc. 
20 Craig Road 
Montvale, New Jersey 07645 

Gentlemen: 

         I am general counsel to Geotek Communications, Inc., a Delaware
corporation (the "Company"), and have served in such capacity in connection with
the proposed exchange (the "Exchange") by the Company of an aggregate of
$227,700,000 principal amount at maturity of 15% Series B Senior Secured
Discount Notes due 2005 (the "Exchange Notes") for an aggregate of $227,700,000
principal amount at maturity of 15% Series A Senior Secured Discount Notes due
2005 (the "Initial Notes"). The Exchange Notes are to be issued under an
Indenture dated as of June 30, 1995 between the Company and IBJ Schroder Bank &
Trust Company (the "Trustee"), as supplemented by that certain Supplemental
Indenture dated as of August 28, 1995 (collectively, the "Indenture").

         I have examined, among other things, the Certificate of Incorporation
and the Bylaws of the Company, the Indenture and the proposed form of Exchange
Note. I also have examined originals or copies, certified or otherwise
identified to my satisfaction, of such corporate records of the Company and
other instruments and documents and statutory and other materials as I have
deemed necessary as a basis for the opinions hereinafter expressed.

         In rendering the opinion below, I have assumed, without any independent
investigation or verification of any kind: (i) the genuineness of all signatures
on, and the authenticity and completeness of, all documents submitted to me as
originals and the conformity to original documents and completeness of all
documents submitted to me as certified, conformed or photostatic copies; (ii)
that the Indenture has been duly authorized, executed and delivered by the
Trustee; and (iii) that the Exchange Notes will be duly authenticated by the
Trustee.

         Based on and subject to the foregoing and subject to the
qualifications, limitations and exceptions contained below, I am of the opinion
that the Exchange Notes have been duly authorized for issuance and when
executed, issued, delivered and exchanged in accordance with the provisions of
the Indenture (including the provisions thereof relating to authentication of
the Exchange Notes by the Trustee), will be entitled to the benefits of the
Indenture and will be valid and legally binding obligations of the Company,
enforceable against the Company in accordance with their terms, except (i) as
limited by applicable bankruptcy, insolvency, reorganization, receivership,
moratorium, fraudulent transfer and conveyance laws and other similar laws of
general application now or thereafter in effect relating to or affecting the
rights and remedies of creditors generally, (ii) as limited by general
principles of equity, whether enforcement is considered in a proceeding in
equity or at law, and the discretion of the court before which any proceeding
therefor may be brought, (iii) the enforceability under certain circumstance
under law or court decisions of provisions providing for the indemnification of
or contribution to a party with respect to a liability where such
indemnification or contribution is contrary to public policy, and (iv) I express
no opinion concerning the enforceability of the waiver of rights or defenses
contained in Section 4.19 of the Indenture.

         The opinions expressed herein are limited to the laws of the State of
New York, the General Corporation Law of the State of Delaware and United States
Federal law. No opinion is expressed on any matters other than those expressly
referred herein. The opinions set forth herein are as of the date of this letter
and I do not render any opinion as to the effect of any matter which may occur
subsequent to the date hereof.

         I hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the reference to me under "Legal Matters" in the
Prospectus forming a part of the Registration Statement. In giving such consent,
I do not admit hereby that I come within the category of persons whose consent
is required under Section 7 of the Securities Act of 1933, as amended, or the
rules and regulations of the SEC promulgated thereunder.

                                                     Very truly yours, 
                                                      
                                                     /s/ Andrew Siegel
                                                     --------------------------
                                                         Andrew Siegel