Thrombectomy catheters are presented that have curved tip portions. A suction lumen extends from at or near the proximal end of the catheter to a suction port at or near the tip portion of the catheter. The curves of the thrombectomy catheter can be selected to place a suction port at or near a vessel wall for the more effective removal of thrombus resulting from directing the suction in the direction of the thrombus. In some embodiments, the tip portion of the catheter can be transitioned from a first configuration for delivery of the catheter into the vessel to a second more curved configuration with a desired design for application of suction. The catheter can be moved in a circumferential and/or lateral direction to cover selected portions of the inner vessel wall. In some embodiments, a partially occlusive structure can be used to reduce and/or redirect flow within the vessel to improve performance of the thrombectomy.