The Hypertension Detection and Follow-up Program (HDFP) data are reported by diastolic blood pressure (DBP) stratum for four race-sex subgroups. For Stratum I (entry DBP 90-104 mm Hg) in each of the race-sex subgroups (black male, black female, white male, and white female). Stepped Care (SC) participants experienced a reduced mortality as compared to Referred Care (RC). For black males and females in all three entry DBP strata, mortality was lower in the SC than RC. Only in three subgroups did the SC mortality exceed RC: Stratum II (entry DBP 105-114 mm Hg) white females and Stratum III (entry DBP 115 + mm Hg) white males and females. Possible explanations for these deviant findings are discussed. The HDFP was designed to determine the difference in total 5-year mortality between SC and RC; subgroup analyses may be subject to large chance variation and must be interpreted with great caution. The value of vigorous treatment of "mild" hypertension (Stratum I) in males and females, black and white, and the value of treatment for all blood pressure strata in blacks are confirmed by this analysis.