Abstract: A car seat alarm system for alerting a parent or caretaker to retrieve the infant child prior to exiting a vehicle is provided. The vehicle has an openable door mounted within a door frame. The car seat alarm system comprises a child car seat having a harness and a fastener positioned on the harness. The fastener is closable to secure the harness around the infant child and openable to unsecure the harness from around the infant child. A transmitting system is mounted on the child car seat. A receiving system is associated with the door and the door frame and directly interfaces with the transmitting system. Upon opening the door from within the door frame, with the fastener dosed to secure the harness around the infant child, the transmitting system provides an alert. The alert reminds the parent or caretaker to retrieve the infant child prior to exiting.