The Minnesota Multiphasic Personality Inventory (MMPI-2) is commonly used in chronic illness and chronic pain populations to assess psychological functioning. We report the results of the first study employing the MMPI-2 to assess psychological aspects of patients with Gaucher disease, type I (GD) is an inborn error of metabolism with unique features as a chronic illness: the disorder often presents with mild symptoms, and is frequently diagnosed in later childhood or adulthood; the treatment is highly efficacious, but, that same treatment is intrusive and expensive and requires that patients restructure their work and personal schedules. In this study, 28 patients with GD completed the MMPI-2 and a background questionnaire. GD patients scored significantly higher than the MMPI-2 normative sample on MMPI-2 scales of Validity (K), Hypochondriasis (Hs), Depression (D), Hysteria (Hy), Psychasthenia (Pt) and Schizophrenia (Sc). Individuals with elevated scores on the Hs, D and Hy scales tend to have somatic concerns and depressed mood. Under stress, they are likely to report physical symptoms. Elevated Pt and Sc scales suggest psychological turmoil and, possibly feelings of isolation. An elevated K scale indicates a tendency for individuals to deny psychopathology. The length of time the patient with GD had been on enzyme replacement therapy was not significantly related to any of the 13 MMPI-2 scales. Cohorts of patients with chronic heart disease (CRHD) and cohorts of patients with chronic pain were utilized as comparative populations in this investigation. The elevated scores of the GD patients on MMPI-2 scales Hs, D and Hy were similar to those of the CRHD population. The chronic pain patients also showed elevations on MMPI-2 scales Hs, D and Hy, which were elevated in the GD patients; the elevations in the chronic pain patients were higher than those shown by the GD patients. We conclude that patients with GD exhibit moderate to severe psychological complications, similar to patients with other long-term chronic illnesses.