IntroductionA prognosis provides valuable information to expected progress and anticipated outcome over the course of care. Although it is known that physical therapists can accurately prognose, it is unknown what factors are utilised in clinical practice.ObjectiveThe purpose of this study was to determine the prognostic domains and factors that influenced a PT's clinical reasoning processes.DesignMixed Methods Design, affirming the prognostic ability of the physical therapists and the qualitative exploration of the prognostic factors considered by physical therapists.MethodsTwenty‐nine physical therapists participated in this study. Participants underwent semi‐structured qualitative interviews that were coded to populate a prognostic framework. In addition, de‐identified patient data was used to determine the ability of the PT to form a prognosis. Linear regression was used to determine if an initial prognostic score was related to function at discharge.ResultsThere were significant relationships (p = <0.05) between the prognosis score and Focus on Therapeutic Outcomes (B = 2.25), Numeric Pain Rating Scale (B = 0.257), and GROC (B = 0.289) upon patient discharge. Qualitative factors were categorised into prognostic domains (prevalence): Mood, Motivation, Pain Behaviours (100%), Disease Severity (93.1%), Health Status (86.2%), Social, Occupation, Environmental (67.0%), and Genetics, Biology, Biomarkers (44.8%). Factors that did not fit established domains were reported and categorised as Other (86.2%).ConclusionOur findings support the relationship between PT prognosis of patients with musculoskeletal pain and patient outcomes. In addition, the domains and factors PTs use to formulate prognosis during evaluation present a complex biopsychosocial framework, suggesting that PTs consider factors from multiple domains when forming a prognosis.