This cross-sectional, correlational study aims to determine the predictors of illness perception and treatment expectations in adults with chronic lateral elbow pain. Sociodemographic characteristics, clinical findings (pain intensity, pain duration, elbow-specific function) and psychosocial variables (pain self-efficacy, fear-avoidance beliefs, pain catastrophizing) will be examined as candidate predictors of two patient-centred constructs: illness perception, measured with the Brief Illness Perception Questionnaire, and treatment expectation, measured with the Treatment Expectation Questionnaire. Data will be analysed using hierarchical multiple linear regression in three predictor blocks. The study is reported according to the STROBE statement.