This paper examines the reliability and stability of developmental idealism (DI) measures in Nepal. DI is a set of cultural schemas that contains beliefs and values favoring modern societies and families over traditional ones and that views modern families as causes and effects of modern societies. It also views the world as dynamic, with change from traditionality toward modernity. Earlier studies have shown that DI has been disseminated widely internationally, but provide little evidence concerning whether individual views of DI can be reliably measured or the extent to which such views are stable across time. We estimate the reliability and stability of DI measures using panel data collected in Nepal. Our results indicate substantial reliability, equal or nearly equal to the reliability of standard value and belief items measured in general American surveys. There is also considerable stability of DI views across our study interval from 2008 to 2011.