A group of 350 migraineurs (87 male, 263 female) and 300 controls without migraine (104 male, 196 female) were questioned about occurrence, in parents, of the atherosclerosis-related diseases (ASRD) of diabetes mellitus (DM), hypertension (HBP), myocardial infarction (MI), and stroke as well as about recurrent severe headache (RSHA). Occurrence of DM, HBP, MI and stroke was compared for mothers and fathers of migraine vs. those of control subjects and no significant differences were found. The mothers and fathers were pooled and resegregated by presence or absence of RSHA and then occurrence of DM, HBP, MI and stroke again compared. For mothers there was increased occurrence of stroke and DM in the RSHA group but the differences were not significant. For RSHA fathers there was increased incidence of MI (p<.10) and HBP (p<.01). Aggregate occurrence of all ASRD was evaluated for RSHA vs. no-RSHA parents. ASRD occurred more frequently in the RSHA than in the no-RSHA parents (p<.05). Breakdown by age showed that this occurred at all ages in men (p<.05) but in women the difference was significant only under age 60 (p<.05). This study suggests that RSHA, which is primarily migraine, may be a risk factor or a marker for occurrence of ASRD.