This study examines the importance of physical and psychological predictors of work sample performance within the Swedish police Counterterrorism Intervention Assessment and Selection (CTIAS) process (N = 160). CTIAS consists of a 4-day prescreening (Phase 1) and a 10-day work sample test (Phase 2). Applicants may withdraw freely or be stopped by a CTIAS board (if they do not fulfill the CTIAS requirement criteria) at any moment throughout Phases 1 and 2. The dependent variable was applicants being approved at the end of CTIAS Phase 1. Biserial correlations were used to determine relationships between the predictors’ age, general mental ability, executive functions, personality, physical strength, coordination, running capacity and the dependent variable. Significant (p < 0.01) results in the biserial correlations were strength (r = 0.217), coordination (r = 0.223), and running capacity (r = 0.412). In conclusion, the logistic regression analysis with all predictors revealed that only running capacity (2800 meters) was significant for approval to CTIAS. Implications for the practical selection of CTIAS are discussed, and suggestions for future investigation are proposed.