Team physicians frequently encounter athletes who have eating disorders. Behavioral contracting may be an effective tool for motivating these patients to implement nutritional changes. An effective contract must be built on five important principles: a collaborative physician-athlete relationship developed over time, patient involvement in setting the terms, appropriate outcome and process goals, a system for monitoring progress, and clearly defined consequences that will be carried out consistently if the contract is broken. As we show, failing to apply basic contracting principles can render treatment ineffective.