Devices and methods for shaping an ablation treatment volume formed in fluid enhanced ablation therapy are provided. The devices and methods disclosed herein utilize the interaction of fluids to create ablation treatment volumes having a variety of shapes. In one embodiment, a method for forming an ablation treatment volume having a desired shape includes delivering therapeutic energy to tissue to form an ablation treatment volume and simultaneously delivering a first fluid and a second fluid to the tissue. The first and second fluids can convect the therapeutic energy in a desired direction such that the ablation treatment volume has a desired shape.