Exhibit 5
                                                    Opinion of Gadsby Hannah LLP

                                GADSBY HANNAH LLP
                               225 Franklin Street
                           Boston, Massachusetts 02110

                                                            May 8, 2001

Technical Communications Corporation
100 Domino Drive
Concord, Massachusetts 01742

     Re:  Registration Statement on Form S-8
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Ladies and Gentlemen:

     We have acted as counsel for Technical Communications Corporation, a
Massachusetts corporation (the "Company"), in connection with the preparation of
the Company's Registration Statement on Form S-8 proposed to be filed with the
Securities and Exchange Commission on or about May 8, 2001 (the "Registration
Statement").

     The Registration Statement covers the registration of shares of common
stock, $0.10 par value per share, of the Company (the "Shares"), which are
issuable by the Company pursuant to its 1991 Stock Option Plan, as amended (the
"Plan").

     We have reviewed the corporate proceedings of the Company with respect to
the authorization of the Plan and the issuance of the Shares thereunder. We have
also examined and relied upon originals or copies of such corporate records,
instruments, agreements or other documents of the Company, and certificates of
officers of the Company as to certain factual matters (including but not
limited to a copy of an amendment to the Plan approved by the Company's
stockholders on February 10, 1997 certified by the Company's Clerk), as we have
deemed necessary or appropriate as a basis for the opinions hereinafter
expressed. In our examination, we have assumed the genuineness of all
signatures, the conformity to the originals of all documents reviewed by us as
copies, the authenticity and completeness of all original documents reviewed by
us in original or copy form and the legal competence of each individual
executing any document.

     This opinion is limited solely to the Massachusetts Corporation Laws, as
interpreted by courts located in Massachusetts, and the reported judicial
decisions interpreting those laws.

     Based upon and subject to the foregoing, we are of the opinion that the
Shares, when issued and delivered upon the due exercise of options or awards
pursuant to the Plan and against the payment of the purchase price therefor, as
specified in such Plan or documents governing such awards, will be validly
issued, fully paid and non-assessable.

     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement.

                                              Very truly yours,

                                              /s/ GADSBY HANNAH LLP
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