As positron emission tomography (PET) imaging is becoming more prevalent in clinical practice, it is reasonable to ask if there will be a role for single photon emission computed tomography (SPECT) in the future. This article considers that question, focusing on areas where SPECT can differentiate itself from PET for fundamental reasons: breadth of available radionuclides, simultaneous imaging of multiple agents, cost-effectiveness and adaptability to specific imaging situations. The conclusion is that SPECT will continue to evolve and exist alongside PET and will grow the field of molecular imaging with improved efficiency and patient workflow.