In everyday life, we are often confronted with morally conflicting social interaction situations. Therefore, the main objective of the present set of studies was the development and validation of a new measure to assess decision-making in everyday moral conflict situations. All vignettes required a decision between an altruistic versus an egoistic behavioral response alternative. In three independent surveys (N = 200), we developed a 40-items measure with preferable mean rates of altruistic decisions (Study 1), clear representation of altruistic and egoistic response classes (Study 2), unambiguousness of social closeness classifications (socially close vs. socially distant protagonists; Studies 1 and 2), and high similarity to reality ratings (Studies 1 and 2). Additionally, we developed two parallelized item sets for future use in within-subjects design studies and investigated the measurement properties of our new scale (Studies 1 and 3). Results of Rasch model analyses and classical test theory fit indices showed unidimensionality and confirmed the appropriateness of the fragmentation into two parallelized item sets. Notably, in our data, there were neither effects of social closeness nor gender on the percentage of altruistic decisions. In sum, we propose the Everyday Moral Conflict Situations (EMCS) Scale as a promising new measurement tool that may facilitate further research in different research areas due to its broad applicability.