Upon learning that their child has a neurodevelopmental disorder, families enter a different process and can experience problems related to their child's behavior management. This study was designed in response to a request from mothers with children diagnosed with various neurodevelopmental disorders. The study used a multi-level case study, one of the qualitative research designs. A behavior support plan (BSP) was created to address the three mothers' needs concerning the negative behaviors they observed in their children. The BSP is a 12-session program based on applied behavior analysis (ABA). This program was shaped by collecting data through semi-structured interviews, field notes, and the researcher's diary before the family education. It was determined whether the program was effective by continuing to collect data through the data collection tools in the middle and end of the BSP implementation. The results of the inductive analysis revealed that BSP reduced the problem behaviors in the children and ended the punishments given by the mothers and that they felt better via this education. In general, it is recommended to train applied behavior analysts who are going to provide individual family education based on ABA, to make family education a country policy, and to increase such education provided to families both at schools and individually.