Family-school partnership is an essential component of the special education process for children with intellectual and developmental disabilities (IDD). Latinx families especially face systemic barriers when participating in education decision-making for their children with IDD. However, few interventions have been developed to facilitate and educate Latinx parents of children with IDD. This study presents findings from a pilot randomized controlled trial, testing a 12-hr intervention to educate Latinx parents of children with IDD to advocate for school services - the Families Included in Receiving Better Special Education Services (FIRME) program. Participants included 26 Latinx parents of children with IDD, randomly assigned to a treatment (N = 11) or wait-list control (N = 15). The FIRME program had acceptable feasibility and treatment fidelity. Intervention group participants demonstrated positive changes following the intervention, including significant increases in special education knowledge, advocacy, empowerment, and decreased parental stress. Findings offer promising evidence of advocacy programs for Latinx families of children with IDD. Implications for research including the need for a fully powered randomized controlled trial are discussed; also, to address parental stress, the FIRME program may need to include ongoing supports.