The Schwartz Model of Basic Values is an influential framework that describes what people find important and worth pursuing in life. The model proposes that ten human values are found cross-culturally, and so significant efforts have gone into empirically testing these claims. While instruments such as the Portrait Values Questionnaire-40 (PVQ-40) reliably discriminated the full set of theorized values, briefer versions have either suffered from a lack of construct validity (PVQ-21) or from not having been put through a rigorous statistical test of its underlying structure (Twenty Item Values Inventory [TwIVI]) via confirmatory factor analysis (CFA). The present study, using a Portuguese sample of adults (n = 524), is the first to examine the factorial structure of the TwIVI via CFA. We apply a magnifying glass approach by testing two separate models, each covering five values, which reflect the Growth and Self-protective dimensions. Moreover, we provide evidences that the TwIVI is reliable and capable of capturing the theorized quasi-circumplex structure, and the cross-cultural gender differences and relative hierarchical importance of values. Finally, we establish criterion-related validity, with values correlating with political identity and social and economic issues.