The aim of this study was to assess the hypothesis that blood donation rates vary with Hispanic ethnicity (family origin in Spanish-speaking countries) in addition to race in the United States. Lower blood donation rates have been reported among African Americans (AAs) compared with non-Hispanic European Americans (EAs). Adequate published reports on donation rates are not available for Hispanic Americans (HAs). Using data from a 2002 national survey, which included 4923 men and 7600 women aged 15–44 years with complete data, we tested the hypothesis using weighted bivariate and multivariate statistics. Among men aged 25–44 years, the percentage [95% confidence limits (95% CL)] with a history of blood donation since 1985 was similar at ages 25–34 years (46%, 42–49) and 35–44 years (41%, 37–45). It was highest in non-Hispanic EA (49%, 45–52%), intermediate in AA (35%, 30–40%) and lowest in HA (30%, 25–36%) (P< 0·001). Other variables significantly (P< 0·01) associated with history of blood donation in bivariate analyses were nativity (United States/other), education (<12/≥12 years), poverty (<200%/≥200% poverty limit) and married (yes/no). Variables that are not significantly associated were age, metropolitan residence (yes/no), receipt of public assistance (yes/no), current labour-force participation (yes/no) and religion raised. Compared with non-Hispanic EA, the adjusted odds ratios were essentially the same for Hispanics 0·66 (95% CL 0·47–0·92) and AAs 0·64 (95% CL 0·49–0·84). Only 34% of women had donated blood, but the association with race/ethnicity was similar. Similar patterns were also seen at ages 15–24 years. HAs and AAs have similar low blood donation rates compared with non-Hispanic EAs. The difference is not explained by sociodemographic variables.