The cases of 2 women with pyoderma gangrenosum (PG) and undifferentiated seronegative spondylarthropathy (SpA) are described. These 2 cases, together with the recently reported case of PG and B27-positive psoriatic spondylarthropathy, suggest that PG may also occur in association with forms of seronegative SpA that are different from primary ankylosing spondylitis (AS) and AS associated with inflammatory bowel disease.