A medical holding arm is described, comprising at least one joint (24, 26, 28, 30, 32) with two joint bodies (40, 42) which are rotatable relative to each other about a rotational axis (D), wherein a first of the joint bodies (40) has a plurality of locking pins (46) and a second of the joint bodies (42) has a plurality of locking recesses (48), the number of locking pins (46) differs from the number of locking recesses (48), the locking pins (46) each have an axially tapered engagement part (66), the locking recesses (48) are respectively formed axially tapered to selectively receive each of the engagement parts (66) for locking the joint (24, 26, 28, 30, 32), and when the joint (24, 26, 28, 30, 32) is locked, at least one of the locking pins (46) is received with its tapered engagement part (66) completely in one of the tapered locking recesses (48), while at least one of the other locking pins (46) is received with its tapered engagement part (66) only partially in one of the other tapered locking recesses (48). The engagement part (66) of the respective locking pin (46) has at least one first flattened contact surface (68), and the respective locking recess (48) has at least one second flattened contact surface (72). When the engagement part (66) of the locking pin (46) is received in the respective locking recess (48), the first and the second contact surface (68, 72) are at least partially in flat contact with each other.