In recent years, the concept of quality of life (QoL) has gained significant importance within health care and clinical research, e.g., as in patient-reported outcomes. In gestational diabetes mellitus (GDM) care, enhancing QoL through reasonable interventions is considered equally important as achieving metabolic control and preventing complications in the treatment process, leading to the suggestion that QoL assessment should be implemented as a clinical standard in GDM care. Although a considerable number of questionnaires for the measurement of general as well as health-related and diabetes-specific QoL are frequently used in GDM research, a validated QoL questionnaire tailored to women with GDM does not exist in German-speaking countries. To develop and test such an instrument, we plan to conduct the following steps: (a) translate the Persian questionnaire GDMQ-36, the only GDM-specific questionnaire to date; (b) conduct expert ratings as well as pretests featuring cognitive debriefings and structured interviews with women suffering from GDM for evaluating comprehensibility, face and content validity; (c) pilot and validate the preliminary questionnaire in terms of testing its psychometric performance (e.g., via confirmatory factor analysis). The resulting GDM-specific questionnaire will facilitate a broader perspective of the pregnant women’s expectations, needs, impairments, and burdens related to their disease, and its treatment. This enables physicians and other health professionals to establish an individualized treatment plan and to provide customized information, support, and psychological counseling, which helps to optimize the provided care.