Dispositional optimism is a widely studied construct in social science and medicine associated with a variety of important psychological and physiological outcomes. Our purpose in this study was to examine coefficient alpha for a popular optimism measure: The Life Orientation Test (LOT; Scheier Carver, 1985). We utilized a meta-analytic procedure known as reliability generalization to provide an aggregate estimate of coefficient alpha across empirical studies that have employed the scale over time and across populations. Furthermore, we identified sample and demographic characteristics associated with variance in coefficient alpha. We discuss conditions associated with variability in coefficient alpha and provide suggestions for continued research for the LOT.