Background: Today’s healthcare organizations are challenged by pressures to meet growing population demands and enhance community health through improving service quality. Quality function deployment is one of the widely-used customer- driven approaches for health services development. In the current study, quality function deployment is used to improve the quality of chemotherapy unit services.Methods: First, we identified chemotherapy outpatient unit patients as chemotherapy unit customers. Then, the Delphi technique and component factor analysis with orthogonal rotation was employed to determine their expectations. Thereafter, data envelopment analysis was performed to specify user priorities. We determined the relationships between patients’ expectations and service elements through expert group consensus using the Delphi method and the relationships between service elements by Pearson correlation. Finally, simple and compound priorities of the service elements were derived by matrix calculation.Results: Chemotherapy unit patients had four main expectations: access, suitable hotel services, satisfactory and effective relationships, and clinical services. The chemotherapy unit has six key service elements of equipment, materials, human resources, physical space, basic facilities, and communication and training. There were four-level relationships between the patients’ expectations and service elements, with mostly significant correlations between service elements. According to the findings, the functional group of basic facilities was the most critical factor, followed by materials.Conclusion: The findings of the current study can be a general guideline as well as a scientific, structured framework for chemotherapy unit decision makers in order to improve chemotherapy unit services.