SYNOPSISMMPI' were obtained from 258 untreated headache patients, of whom 113 were males and 145 females. The diagnostic headache categories included: 1. Migraine alone; 2. Chronic scalp muscle contraction headache (SMC); 3. Combination headache (migraine and SMC); 4. Cluster headache; 5. Post‐traumatic cephalgia (P‐T); 6. conversion cephalgia.Mean scores of the validity and clinical scales were calculated and compared between diagnostic categories; males considered separately from females. As a result of this comparison, three significantly distinct groups, two categories per group, were obtained; Group A, migraine and cluster; Group B, SMC and combination headaches; Group C, P‐T and conversion cephalgia. This grouping applied to women and men similarly.In a spectrum of from most normal to most neurotic patterns, Group A was followed by Groups B and C respectively. Significant "conversion v" patterns were found in women with SMC, P‐T, and conversion cephalgia, and in men with combination headache.In an effort to determine the predictability of correct diagnoses from MMPI patterns, selective criteria were generated and tested in a blind fashion using an additional 83 coded MMPI'. The accuracy of predictability exceeded the .00