Optimal image quality is an ideal in nuclear medicine that is not always realized, being subject to a variety of conditions that can act, either singly or in combination, to undermine its accomplishment. These conditions include potential defects and limitations in both the hardware and software used for the acquisition and reconstruction of nuclear medicine images. Factors relating to individual patients can contribute to these obstacles, including limitations in mobility and compliance. Importantly, suboptimal or erroneous technique is a common source of poor imaging results, with loss of diagnostic efficacy. Appropriate test selection and careful attention to patient preparation and procedural details are essential elements in avoiding image flaws and artifacts in nuclear medicine.