A 64-year-old man was given a diagnosis of CD16+ CD56- natural killer cell-lineage granular lymphocyte proliferative disorder (NK-GLPD) with Coombs-negative autoimmune hemolytic anemia (AIHA). Two courses of 1,000 mg intravenous methylprednisolone for 3 days were transiently effective for both AIHA and NK-GLPD. On the recurrence of AIHA, NK-GLPD also re-appeared. The same treatment was effective in controlling both diseases again. This was a rare case of NK-GLPD combined with autoimmune disease.