A positioning device for a cymbal has a bracket, a clamp, a cymbal supporting assembly, two friction pads and a primary adjusting assembly. The bracket has a stationary clamping member. The clamp is mounted movably on the bracket and has a movable clamping member. The cymbal supporting assembly is mounted pivotally between the stationary clamping member of the bracket and the movable clamping member and has a friction wheel and a cymbal supporting rod. One of the friction pads is mounted between the stationary clamping member and one side of the friction wheel. The other friction pad is mounted between the movable clamping member and the other side of the friction wheel. The friction pads selectively presses respectively against the sides of the friction wheel of the cymbal supporting assembly. The positioning device with the friction pads precisely sets the angular position of the cymbal.