Successfully conducting military operations requires proficient multitasking. Thus, it is essential to sufficiently assess soldiers’ multitasking abilities before deployment to predict their success in the open field. There are two established approaches to operationalize multitasking: either using a multi-/dual-task paradigm or assessing individuals’ performance in several subtasks building a cohesive multitasking scenario. However, it is unclear if and which approach may be more suitable for predicting military multitasking. To investigate this, we recruited 25 students/officer candidates of the University of the Bundeswehr in Munich to perform multitasking based on a dual-task paradigm and a multitasking scenario in the laboratory, and military multitasking in a shooting gallery. For the dual-task, individuals were asked to solve math equations and memorize radio signals in single- compared to dual-task conditions. For the multitasking scenario, individuals were required to perform the multi-attribute task battery (MATB), which includes four subtasks to simulate a flight scenario. For military multitasking, individuals were supposed to execute a shooting exercise and perform the same math and radio tasks as performed in the laboratory in single-/dual- and triple -task conditions, simultaneously. We expected the dual-task assessment in the laboratory to predict military multitasking better, given that both tasks shared very similar task requirements. In contrast, we found moderate evidence in favor of individuals’ MATB performance serving as the best predictor of military multitasking, using Bayesian hierarchical regression analyses. Thus, multitasking scenario performance may be more suitable for predicting military multitasking. A general multitasking ability might explain this effect.