An association between complete congenital heart block (CCHB) and anti-Ro/SSA antibody is well recognized but has never been reported in Thailand. We report here a 37-year-old female who was admitted because of massive epistaxis secondary to immune thrombocytopenia. She had given birth to a child with CCHB 2 years previously, when she was healthy. Antinuclear antibody and anti-Ro/SSA were positive in her sera, but were negative in her son. The relationship between anti-Ro/SSA antibody and outcome of mothers with infants with CCHB is reviewed.