Background: Medical professional liability complaints are not triggered by a single factor, but rather by multiple factors, each having more or less implications, such as the characteristics of the physician, the medical system, the patients, the complexity of their pathology, and the inherent limits of medicine. Knowledge about the factors that initiate the complaint procedure is essential to identify the targeted measures to limit their prevalence and impact. The purpose of this study was to identify the reasons behind the malpractice complaints and the factors that may influence the initiation of complaints by the patients. Material and Methods: This study was conducted using an online questionnaire, addressed to Romanian doctors, with questions about the reasons for patient dissatisfaction and complaints, the factors that predispose a physician to being complained against, and the protective factors against patient complaints. Results: The study group included 1684 physicians, of whom 16.1% were themselves involved in a complaint, and 52.5% knew of a colleague who was complained against. The opinions of the participants regarding the reasons for the complaints, the predisposing factors to complaints, and the factors that contributed to the reported incident showed a strong link between professional liability complaints and the physician–patient/patient’s family relationship. The relationship between fellow physicians is additional to this. Conclusion: This study reveals that the improvement in the relational aspects of medical practice (physician–patient relationship and relationship between physicians) has the highest potential to decrease the number of malpractice complaints. Its practical relevance is related to the need for training physicians in the relational aspects of medical practice during academic years and throughout their career.