Provided are a medical image processing apparatus, an endoscope system, and a method for operating a medical image processing apparatus, which suppresses saturation enhancement of an observation target included in a high saturation range and enhances the visibility of the observation target by expanding the high saturation range. . As the saturation emphasis processing, a first saturation emphasis processing or a second saturation emphasis processing different from the first saturation emphasis processing is performed. The high saturation range Ry (rc) Ry (r2) after the second saturation enhancement processing is made larger than the high saturation range Rx (rc) Rx (r2) after the first saturation enhancement processing. The value Ry (r) included in the high saturation range Ry (rc) Ry (r2) after the second saturation enhancement processing is a value included in the high saturation range Rx (rc) Rx (r2) after the first saturation enhancement processing. It is smaller than Rx (r).高彩度の範囲に含まれる観察対象の彩度強調を抑制し、高彩度の範囲を広げることで観察対象の視認性を高める医用画像処理装置及び内視鏡システム並びに医用画像処理装置の作動方法を提供する。 彩度強調処理として、第１彩度強調処理、又は前記第１彩度強調処理と異なる第２の彩度強調処理を行う。第２彩度強調処理後の高彩度範囲Ｒｙ（ｒｃ）Ｒｙ（ｒ２）を、第１彩度強調処理後の高彩度範囲Ｒｘ（ｒｃ）Ｒｘ（ｒ２）よりも大きくする。第２彩度強調処理後の高彩度範囲Ｒｙ（ｒｃ）Ｒｙ（ｒ２）に含まれる値Ｒｙ（ｒ）は、第１彩度強調処理後の高彩度範囲Ｒｘ（ｒｃ）Ｒｘ（ｒ２）に含まれる値Ｒｘ（ｒ）よりも小さい。
