Although the success rates and complications of various treatment options for children with intractable epilepsy have been described, the actual expectations of parents for these treatments are less clear. Since 1998, parents at our institution have written their goals in a letter before starting their children on the ketogenic diet. One hundred consecutive letters were evaluated. The most common first goal was seizure improvement, second was anticonvulsant reduction, and third was cognitive improvement. Ninety percent requested improvement in cognition or alertness. These expectations were either met or exceeded at 6 months in 52-60% of children. Achieving or surpassing parental expectations for cognitive improvement correlated with longer diet duration (P=0.04), but meeting goals for seizure or anticonvulsant reduction did not. Cognitive improvement (P<0.001) and >90% seizure reduction (P=0.04) at 6 months positively correlated with longer eventual diet duration. Expectations for cognitive improvement need to be discussed prior to beginning the ketogenic diet.