Currently, the number of people with physical disability and impairment is increasing significantly in Ethiopia, especially in the northern part. In that regard, the Ethiopian government has been providing physical rehabilitation services to recover patients. However, due to the widespread problem of healthcare service and the increase in patients seeking physiotherapy service, the quality of the service might be compromised, and the evidence is limited. Thus, this study aimed to evaluate the quality of physiotherapy services at the University of Gondar Comprehensive Specialized Hospital, northwest Ethiopia. A single case study with concurrent mixed method research design was conducted from June 02- August 10, 2022. The evaluation used patient-centeredness, timeliness, compliance and availability dimensions with 27 indicators. A total of 415 systematically selected patients who came for physiotherapy service for exit interviews, 9 service providers and managers for key-informant interviews, and 8 patients for in-depth interviews participated in the study. Approximately 176 patient medical charts were reviewed, and direct observation of 14 patient-provider interactions was performed. Binary logistic regression analysis was computed to identify factors associated with patient-centeredness. In the final model, variables with a p value < 0.05 and adjusted odds ratio (AOR) with 95% confidence interval (CI) were used to declare statistical significance. Thematic analysis for the qualitative data using OPEN CODE version 4.03 was performed. Finally, the dimensions and overall quality of physiotherapy service were judged using predetermined criteria. The overall quality of the physiotherapy service was found to be fair or intermediate (66.5%), computed from the availability of resources 63.4%, compliance of service providers 68.6%, timelines 64.2%, and patient centeredness 73.1%. Qualitative findings also revealed that insufficient staffing and heavy workload, lack of resources, inconvenient facilities, relocation of resources in the academic division of physiotherapy department, lack of training and continuous professional development opportunities, lack management attention and institutional support and nonexistence of multidisciplinary approaches leads to significant gaps in quality service delivery. Attending primary school (AOR = 3.22, 95% CI: 1.56, 6.61), secondary (AOR = 4.24, 1.91, 9.41), and higher education (AOR = 4.79, 1.94, 11.84) and being a private employee (AOR = 0.34, 95% CI: 0.16, 0.76) were significantly associated with patient centeredness. The overall quality of physiotherapy service was deemed intermediate and needs further improvement. The required resources, such as clinical assessment tools, therapeutic exercise equipment, electrotherapy modalities and infrastructure, were not adequate. Educational level and occupation were significantly associated with patient centeredness.