The vote of no confidence is a central mechanism in parliamentary democracies, serving as a key institutional expression of the executive’s responsibility to the legislature. Despite its importance, the conceptualization and operationalization of the vote of no confidence remains underdeveloped. This paper addresses this gap by conceptualizing the vote of no confidence within a broader framework of confidence relations, which also includes the votes of investiture and confidence. It then operationalizes it, identifying categorical institutional indicators of the parliamentary process and uniting them into an index variable for the overall procedural process. Empirically, the study examines 20 parliamentary democracies to test the developed indicators and identify patterns in the institutional design of no-confidence votes. The results of the empirical analysis show a low internal consistency in the proposed index variable for the vote of no confidence—measured through Cronbach’s alpha—which poses a common issue in institutional comparative studies, especially in small-N comparative research. While low alpha scores are typically seen as a normal methodological limitation, and substantive significance can justify the continued use of such variables, if the final index variable fails to accurately capture the phenomenon and merely averages its indicators, it may undermine the variable’s applicability and reliability in future research. This paper engages with this methodological issue, offering solutions for balancing theoretical validity and empirical reliability. The study contributes to ongoing debates about measurement in institutional research and provides a refined approach for analyzing parliamentary dynamics, with potential applications in cross-national studies of legislative-executive relations.