Objectives: To provide initial evidence for the construct, concurrent, and predictive validity of the Team-Referent Attributions Measure in Sport (the TRAMS). Design: Cross-sectional in Studies 1 and 2, and multiple time points in Study 3. Method: Study 1 required participants (N=500) to complete the TRAMS for their "least successful" and "most successful" performances in the preceding three months. In Study 2, after performance, participants (N=515) completed the TRAMS and the Causal Dimension Scale for Teams (CDS-T; Greenlees etal., 2005). Study 3 required participants (N=165) to complete a measure of pre-competition collective-efficacy prior to performance (Day 1, Time 1), the TRAMS following performance (Day 1, Time 2), and a measure of subsequent collective-efficacy prior to subsequent performance (Day 7-9, Time 3). Results: Study 1 supported the factor structure of the TRAMS across least successful and most successful conditions. Study 2 provided further support for the factor structure of the TRAMS, together with evidence of concurrent validity with subscales of the CDS-T. Study 3 revealed, following team defeat, interactions between controllability and generalisability dimensions: Controllability had a significant effect upon subsequent collective-efficacy when causes of team defeat were also perceived to generalise across situations and/or across teams. Following team victory, stable attributions were positively associated with subsequent collective-efficacy. Conclusions: This article provides initial evidence for the validity of the TRAMS and demonstrates for team-referent attributions the theoretical advantages of examining a broader conceptualisation of generalisability attributions and interactive effects of attributions.