Background: Some adults with intellectual disabilities do not acquire oral feeding skills and are dependent on gastrostomy tube supplementation. Methods: Two adults with intellectual and multiple disabilities received intervention for oral consumption during daily meals (standardised food and liquid quantities, individualised procedural guidelines, and consumption-contingent consequences) while the frequency and amount of gastrostomy tube feedings were gradually decreased and eliminated. Results: Compared to baseline (pre-intervention) conditions, the adults increased oral consumption of food and liquid during the intervention and gastrostomy tube supplementation was eliminated. These intervention results continued through multiyear follow-up, one participant lost considerable weight, the second participant maintained weight, and both participants had good health (no hospitalisations, illnesses, and missed medications) and benefited from eating daily meals among their peers. Conclusions: Behaviourally-based intervention with interdisciplinary collaboration and appetite stimulation strategy can establish and improve oral feeding in adults with intellectual and multiple disabilities who were previously gastrostomy tube dependent.