>>>>No, It didn't work in Access (2003).
>>>>
>>>Thanks, I guessed so.
>>
>>Give to me the primary key.
>
>My colleague is not here yet, I'll get back to you.

try this:

select * from Visits V
WHERE EXISTS(SELECT*FROM Visits
                    WHERE patient_name=V.patient_name
                      AND visit_date=V.visit_date
                      AND pkey<>V.pkey)