A dual-instrument resectoscope which includes an outer sheath having a distal portion that is inserted into a body cavity, a proximal portion that remains outside the body, and a longitudinal axis, referenced X; an optical system, for viewing the body cavity from said proximal portion, said optical system including an optical tube, located within said outer sheath and extending throughout the length of said outer sheath, an eye piece and a light source at said proximal portion, in communication with said optical tube, and an endoscope at said distal portion, in communication with said optical tube; first and second surgical instruments, located at said distal portion, for performing surgery in the body cavity; a first transmission mechanism, in communication with said first surgical instrument, and a second transmission mechanism, in communication with said second surgical instrument, each of said first and second transmission mechanisms providing its respective surgical instrument with independent motion, said transmission mechanisms being located at said proximal portion; a first instrument guide, for providing communication between said first transmission mechanism and said first surgical instrument, and a second instrument guide, for providing communication between said second transmission mechanism and said second surgical instrument, said first and second instrument guides being located within an instrument tube located within said outer sheath and extending from said proximal portion to said distal portion; a single actuator, located at said proximal portion, for actuating motions with any of said first transmission mechanism and said second transmission mechanism; and an instrument-selecting component for selectably engaging said single actuator with any of said first and second transmission mechanisms, for providing any one of said first and second surgical instruments with independent motion.