A pruning hook includes a handle unit, an adjusting unit mounted on the handle unit and a cutting unit mounted on the adjusting unit. The adjusting unit includes a support member mounted on the handle unit, a fastening member releasably mounted on the support member and an adjusting member having a first end provided with an adjusting ball rotatably mounted between the support member and the fastening member and a second end provided with a locking tube connected with the cutting unit. Thus, the adjusting ball of the adjusting member is rotatable and movable between the support member and the fastening member so as to adjust the angle and position of the cutting unit relative to the handle unit in a spherical and three-dimensional manner.