Provided are an endoscope system, a processor device, and a method for operating the endoscope system that enable easier and more robust determination of an imaging scene than in the related art and automatic setting of conditions for imaging or image processing appropriate for the imaging scene. An endoscope system 10 includes: an image acquiring unit 54 that acquires an endoscope image obtained by imaging an observation target； a baseline information calculating unit 86 that calculates baseline information by using the endoscope image or a display endoscope image 101 generated by using the endoscope image, the baseline information being information about light scattering characteristics or light absorbing characteristics of the observation target and information that is at least not dependent on particular biological information； an imaging scene determination unit 87 that determines the imaging scene by using the baseline information； and a condition setting unit 88 that sets a condition for imaging or image processing, by using a determination result of the imaging scene determination unit.
