A catheter pump intended to be inserted in the circulatory system, for example for assisting the heart, including a hollow catheter, a sheath, a drive cable, a drive shaft, a propeller, a proximal housing, a distal housing, and several filaments. Axial movement of the sheath in relation to the catheter brings the distal housing closer to the proximal housing so that said filaments are unfolded to form a cage. The propeller is pivotable between a first folded position, in which the propeller is parallel with the drive shaft and an unfolded position in which the propeller is perpendicular to the drive shaft. Axial movement of the sheath in a first movement unfolds the cage and in a second subsequent movement, actuation pins of the sleeve act upon a cam surface that unfolds the propeller.