A medical or surgical instrument, preferably of the pincers, scissors and/or forceps design, includes at least two legs pivoted relative to each other in a pivoting plane and lockable in at least one pivoting direction and in at least one pivoting position. The legs include locking portions adapted to be brought into locking engagement with each other, with the locking portions offset against each other normal to the pivoting plane by such offset that, when the legs are pivoted in the pivoting plane, the locking portions laterally pass each other in the pivoting plane without getting into locking engagement with each other. The medical or surgical instrument is configured in such way that the locking engagement of the locking portions is implemented only by applying a transverse force normal to the pivoting plane to at least one of the legs while cancelling the lateral offset.
