This study validates a novel, modern wrist and hand functional assessment: the Modern Activity Subjective Survey of 2007 (MASS07). In total, 326 patients visiting an academic tertiary-care orthopaedic hand clinic (April 2006-April 2007) were recruited to complete the MASS07 questionnaire, Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, and Patient-Rated Wrist Evaluation (PRWE) to assess construct validity, criterion validity and test-retest reliability of the MASS07. MASS07 correlated strongly with both PRWE (0.81) and DASH (0.85) even when adjusted for age, sex and history of hand problems (Ptextless0.001). MASS07 scores compared for 42 patients with repeated visits indicated no statistically significant difference between MASS07 scores at the patients' first and second clinic visit. We conclude that the newly constructed MASS07 instrument is valid and reliable with respect to the outpatient population with a wide spectrum of hand and wrist pathologies for fast and effective assessment of patient-reported hand function during modern daily activities.