Objectives This study aimed to determine the relationship between frequently used patient-reported outcome (PRO) measures and a multi-task performance outcome (PerfO) measure of general physical function (PF) and to examine the association of these measures with depressive mood, pain, and age. Methods Frequently used PRO measures of general PF (Patient-Reported Outcomes Measurement Information System [PROMIS] PF item bank, PROMIS PF Short Form 20a, Short Form 36 Physical Function Scale) and a PerfO test battery, namely, the Physical Performance Test (PPT), were administered to 78 adult patients from 3 inpatient clinics (cardiology and angiology, rheumatology and clinical immunology, and psychosomatic medicine) at Charité – Universitätsmedizin Berlin. Pearson correlations were used to investigate the associations between PRO measures and the PPT. To explore the predictive value of age, depressive symptoms, and pain intensity, we conducted multiple linear regression analysis for each PF measure. Results We found strong linear relationships between PRO measures and PPT sum scores. Correlations between PPT sum scores and PROMIS PF T-scores were r > 0.75. For all PRO and PerfO measures, age was a predictor of general PF whereas depressive mood was not found to be a relevant predictor. Moreover, pain intensity was found to be a significant predictor of PRO measures but not for PPT sum scores. Conclusions Our findings suggest that frequently used PRO measures and a multi-task PerfO measure of general PF can be used to measure a common PF construct. Nevertheless, PF scores based on PRO measures should ideally be controlled for self-rated pain intensity.