POWER OF ATTORNEY

     Know all by these presents, that the undersigned hereby constitutes and
appoints each of Marc Becker, Michael Esposito and Robert E. Puopolo, signing
singly, the undersigned's true and lawful attorney-in-fact to:

        (1)     execute for and on behalf of the undersigned, in the
                undersigned's capacity as an officer and/or director of CRISPR
                Therapeutics AG (the "Company"), (i) Form ID, including any
                attached documents, to effect the assignment of codes to the
                undersigned to be used in the transmission of information to the
                United States Securities and Exchange Commission using the EDGAR
                System, and (ii) Forms 3, 4 and 5 and amendments thereto in
                accordance with Section 16(a) of the Securities Exchange Act of
                1934, as amended, and the rules thereunder;

        (2)     do and perform any and all acts for and on behalf of the
                undersigned which may be necessary or desirable to complete and
                execute any such Form 3, 4 or 5 and amendments thereto and
                timely file such form with the United States Securities and
                Exchange Commission and any stock exchange or similar authority;
                and

        (3)     take any other action of any type whatsoever in connection with
                the foregoing which, in the opinion of such attorney-in-fact,
                may be of benefit to, in the best interest of, or legally
                required by, the undersigned, it being understood that the
                documents executed by such attorney-in-fact on behalf of the
                undersigned pursuant to this Power of Attorney shall be in such
                form and shall contain such terms and conditions as such
                attorney-in-fact may approve in such attorney-in-fact's
                discretion.

     The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might or
could do if personally present, with full power of substitution or revocation,
hereby ratifying and confirming all that such attorney-in-fact, or such
attorney-in-fact's substitute or substitutes, shall lawfully do or cause to be
done by virtue of this Power of Attorney and the rights and powers herein
granted. The undersigned acknowledges that the foregoing attorneys-in-fact, in
serving in such capacity at the request of the undersigned, are not assuming,
nor is the Company assuming, any of the undersigned's responsibilities to comply
with Section 16 of the Securities Exchange Act of 1934, as amended. The
undersigned hereby agrees to indemnify the attorney-in-fact and the Company from
and against any demand, damage, loss, cost or expense arising from any false or
misleading information provided by the undersigned to the attorney-in-fact.

     This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4 and 5 with respect to the
undersigned's holdings of and transactions in securities issued by the Company,
unless earlier revoked by the undersigned in a signed writing delivered to the
foregoing attorneys-in-fact. This Power of Attorney may be filed with the United
States Securities and Exchange Commission as a confirming statement of the
authority granted herein. This Power of Attorney supersedes any prior power of
attorney in connection with the undersigned's capacity as an officer and/or
director of the Company. This Power of Attorney shall expire as to any
individual attorney-in-fact if such attorney-in-fact ceases to be an executive
officer of, or legal counsel to the Company.

     IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of September 7, 2016.

                                                /s/ Pablo Cagnoni
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                                                     Signature

                                                   Pablo Cagnoni
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