The purposes of the research were (1) to develop the physical therapy practical assessment system by using the multisource feedback (MSF) approach and (2) to investigate the effectiveness of the implementation of the developed physical therapy practical assessment system. The development of physical therapy practical assessment system by using MSF was determined by nine experts in physical therapy. Suitability and feasibility of the system for each sub-group were investigated. Five input factors, two process factors, two output factors, and two feedback factors were involved in the system. Level of suitability and feasibility of elements in each sub-group presented at high to the highest level. In system testing, 40 physical therapy students were participated. Raters consisted of clinical educators, students (self-assessment), friends (students who in the same practical group), and patients. Twice assessments during the period of clinical practice were performed. Data analysis for generalizability coefficient (G-coefficient) was evaluated by the EduG program. Quality of the system was evaluated 4 aspects including the utility, feasibility, propriety, and accuracy. These were calculated by mean (x-bar) and standard deviation (SD). The values of G-coefficient for absolute and relative were 0.86 and 0.88, respectively. In addition, quality of the system showed value at high to the highest level in all aspects.