Background: The present study investigated the impact of the COVID-19-related rehabilitation services lockdown on the mental health of caregivers of children with neurodevelopmental disabilities. Methods: Between 26 March and 11 May 2020, 84 caregivers filled out ad-hoc and standardized questionnaires through an online survey in order to measure their psychological response to the emergency and lockdown as well as their levels of parenting stress, anxiety and depression. Results: Worries about COVID-19 contagion and concerns for the child left without rehabilitation programs were the greatest sources of mental health burden for caregivers. Nonetheless, only the concerns for the child were significantly associated with caregivers' reports of stress, depressive and anxious symptoms. Conclusions: These findings highlight the burden faced by caregivers of children with neurodevelopmental disabilities during the COVID-19 emergency in Italy. These families should be considered as a high-risk population that requires dedicated healthcare attention, such as promoting continuity of care by investing in tele-rehabilitation programs.