We identified factors associated with the empowerment of Japanese families using the Family Empowerment Scale (FES) to contribute to the improvement of empowerment in Japanese families raising a child with developmental disorders (DDs). The study was conducted in 350 caregivers who raised children aged 4-18 years with DDs in urban and suburban districts in Japan. Multiple regression analysis of data collected from 275 respondents revealed that a decrease in family empowerment level correlated with a higher number of siblings reared together, a shorter period since the diagnosis was made, and lower awareness of social support and self-efficacy in caregivers. Medications, possession of an intellectual disability certificate, infrequent hospital visits of the child, disuse of local services by caregivers, and young caregivers also correlated with a lower level of empowerment in the Japanese family.