                                 EXHIBIT NO. 5.1

                     OPINION AND CONSENT OF DUANE MORRIS LLP

                          [Duane Morris LLP Letterhead]


August 12, 2002


NBT Bancorp Inc.
52 South Broad Street
Norwich, New York 13815

Gentlemen:

         We have acted as counsel to NBT Bancorp Inc. (the "Company"), in
connection with the preparation and filing with the Securities and Exchange
Commission under the Securities Act of 1933, as amended, of a registration
statement on Form S-8 (the "Registration Statement") relative to the offer and
sale by the Company of up to 1,000,000 shares (the "Shares") of common stock,
par value $.01 per share ("Common Stock"), pursuant to the NBT Bancorp Inc.
401(k) and Employee Stock Ownership Plan, as amended (the "Plan").

         As counsel to the Company, we have examined and relied upon originals
or copies, authenticated or certified to our satisfaction, of all such corporate
records of the Company, including the resolutions of the Company's board of
directors and other records relating to the authorization, registration, sale,
and issuance of the Shares, 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, we are of the opinion that the Shares to be
issued by the Company as described in the Registration Statement, when issued in
accordance with the terms and conditions of the Plan, will be 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.

                                            Sincerely,


                                            /s/ DUANE MORRIS LLP



