|| The purpose of this study was to investigate the psychological needs of children and adolescents with eating disorders (ED) directed toward their mothers. Patients with ED have low self-assertion and various abnormal eating behaviors. Therefore, mothers face difficulty in understanding their children's psychological needs, and the mother-child relationship is sometimes strained. We developed a One-Message Question (OMQ)-structured interview. The OMQ was easy to answer, and it helped the patients with ED. We examined the relationship between psychological needs and illness phase of the children and adolescents, and we discuss the viability of implementing the OMQ in clinical settings. The subjects were 23 patients and their parents. Their parents were just asked about the patients' background. The mean age of the patients was 15.8 years, and the average age of ED onset was 13.5 years. The EDs were anorexia nervosa (n＝20) and bulimia nervosa (n＝3). The phases of patients' illness were identified as anorexic (n＝5), bulimic (n＝7), chronic (n＝3), and stable (n＝8). All subjects provided specific responses to the OMQ-structured interview. Data analyses revealed the following seven categories of patients' psychological needs directed toward their mothers:attachment, cooperation in meeting their goals, longing for love, changing attitude toward family members, respect for self-reliance, expression of apology, and expression of appreciation. These findings suggested that the OMQ-structured interview may prove useful for mothers to understand their children's psychological needs and may encourage positive interactions as a foundation for future recovery.