In 42 patients with hidradenitis suppurativa surveyed, ten associated instances of marked anemia were found. Any patient with a concomitant systemic disease was eliminated from the study. All ten patients with marked anemia had severe hidradenitis suppurativa a minimum of two years. The 42 cases of hidradenitis suppurativa reviewed were consecutive and not selected for duration. Further studies on the relationship between hidradenitis suppurativa and anemia are indicated.