BackgroundThe WHO-5 well-being index is a brief rating scale extensively used to evaluate well-being symptoms. Despite the increasing number of studies validating this instrument across different samples from different countries, its psychometric properties remain unexplored in the Philippine context. Bridging this gap, the present study assessed the psychometric properties of the WHO-5 in Filipinos amid the pandemic.MethodsIn study one, exploratory structural equation modeling (ESEM) was conducted using a sample of Filipinos (N = 2,521) from the general population and a unidimensional model of well-being was extracted. In study two, confirmatory factor analysis (CFA) was employed to examine the one-factor model in 1,289 Filipino government workers. In study three, nomological validity was examined by performing a mediation analysis using 407 Filipino left-behind emerging adult children with dysfunctionality as mediator, pandemic-related adversities as independent variable, and well-being as the dependent variable.ResultsThe results of ESEM and CFA provided support for the WHO-5 one-factor model. Moreover, the negative relationship of well-being to anxiety, depression, and distress lend evidence to the scale’s criterion validity. The results of the mediation analysis performed in study three implied that those who experienced pandemic-related adversities tended to have greater dysfunctionality, and in turn, had lower levels of well-being.ConclusionsOverall, the findings suggest that the WHO-5 well-being index is a psychometrically sound tool for measuring Filipinos’ well-being.