To investigate chronic immune effects of polychlorinated biphenyl (PCB) and polychlorinated dibenzofuran (PCDF), anti-SSA/Ro and anti-SSB/La antibodies were studied in serum of 213 patients with Yusho and 63 control subjects in 2013. Anti-SSA/Ro antibodies were found in 4.2％ (9/213) of patients with Yusho and 1.6％ (1/63) of control subjects. The prevalence rates of anti-SSA/Ro antibodies in Yusho patients were not associated with blood PCB concentration or blood 2,3,4,7,8-pentachlorodibenzofuran (PeCDF) concentration. Anti-SSB/La antibodies were found in 1.4％ (3/213) of patients of Yusho, but none of controls. Furthermore, high concentrations of PCB and 2,3,4,7,8-PeCDF were present in Yusho patients with anti-SSB/La antibodies. We conclude that anti-SSB/La antibody is present in patients with Yusho, and it may be associated with PCB and 2,3,4,7,8-PeCDF in the blood.